diff --git a/tools/export_thirdparty_catalog_xlsx.py b/tools/export_thirdparty_catalog_xlsx.py
new file mode 100644
index 0000000..395b73e
--- /dev/null
+++ b/tools/export_thirdparty_catalog_xlsx.py
@@ -0,0 +1,396 @@
+#!/usr/bin/env python3
+"""把第三方 ERP 商品工作簿转换为后续商品目录导入使用的规范 CSV。
+
+这个工具只读取 XLSX、在指定目录写 CSV；不发送 HTTP 请求，也不会连接数据库。
+部分第三方工作簿把 OOXML 工作表 dimension 错写成 A1，不能用依赖 dimension 的
+Excel 读取器。本工具直接流式读取工作表 XML，因此能稳定处理这类大文件。
+"""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import re
+import sys
+from collections import Counter
+from dataclasses import dataclass
+from pathlib import Path
+from tempfile import NamedTemporaryFile
+from typing import Iterator
+from urllib.parse import parse_qs, urlparse
+from zipfile import ZipFile
+
+from lxml import etree
+
+
+SPREADSHEET_NS = "{http://schemas.openxmlformats.org/spreadsheetml/2006/main}"
+ROW_TAG = SPREADSHEET_NS + "row"
+CELL_TAG = SPREADSHEET_NS + "c"
+TEXT_TAG = SPREADSHEET_NS + "t"
+VALUE_TAG = SPREADSHEET_NS + "v"
+INLINE_TEXT_TAG = SPREADSHEET_NS + "is"
+GOODS_ID_PATTERN = re.compile(r"^\d{5,20}$")
+PDD_HOSTS = {"mobile.pinduoduo.com", "mobile.yangkeduo.com"}
+
+REQUIRED_HEADERS = (
+    "Parent SKU",
+    "产品标题",
+    "sku",
+    "变种属性名称一",
+    "变种属性名称二",
+    "变种属性值一",
+    "变种属性值二",
+    "主图（URL）地址",
+    "来源URL",
+    "店铺名",
+    "产品id",
+)
+
+# 每个输入数据行对应一条规范 CSV 行。后续接口提交器按商品 ID 去重即可。
+CSV_FIELDS = (
+    "source_file",
+    "source_row",
+    "source_updated_at",
+    "shopee_goods_id",
+    "shopee_title",
+    "shopee_status",
+    "shopee_shop_name",
+    "shopee_image_url",
+    "shopee_main_sku_code",
+    "shopee_sku_id",
+    "shopee_sku_code",
+    "spec_raw",
+    "color",
+    "size",
+    "advice",
+    "parse_ok",
+    "pdd_goods_id",
+    "pdd_goods_url",
+    "pdd_title",
+    "pdd_shop_name",
+    "association_shopee_goods_id",
+    "association_pdd_goods_id",
+    "source_pdd_url",
+    "pdd_importable",
+    "validation_code",
+)
+
+
+class CatalogExportError(RuntimeError):
+    """源工作簿不符合可转换要求。"""
+
+
+@dataclass(frozen=True)
+class ExportResult:
+    """一个输入工作簿的导出统计。"""
+
+    source: Path
+    output: Path
+    rows: int
+    valid_pdd_rows: int
+    validation_counts: tuple[tuple[str, int], ...]
+
+
+def text_of(element: etree._Element) -> str:
+    """合并 OOXML 富文本的所有文本节点。"""
+
+    return "".join(element.itertext()).strip()
+
+
+def column_index(cell_reference: str) -> int:
+    """把 A、AA 等 Excel 列号转成从零开始的索引。"""
+
+    letters = "".join(character for character in cell_reference if character.isalpha())
+    value = 0
+    for character in letters.upper():
+        value = value * 26 + ord(character) - ord("A") + 1
+    return value - 1
+
+
+def read_shared_strings(archive: ZipFile) -> list[str]:
+    """按需读取 shared strings；当前来源主要使用 inlineStr。"""
+
+    try:
+        handle = archive.open("xl/sharedStrings.xml")
+    except KeyError:
+        return []
+    with handle:
+        return [
+            text_of(element)
+            for _, element in etree.iterparse(handle, events=("end",), tag=SPREADSHEET_NS + "si")
+        ]
+
+
+def cell_value(cell: etree._Element, shared_strings: list[str]) -> str:
+    """读取一个 OOXML 单元格的文本值，不依赖错误的 dimension。"""
+
+    cell_type = cell.get("t", "")
+    if cell_type == "inlineStr":
+        inline = cell.find(INLINE_TEXT_TAG)
+        return text_of(inline) if inline is not None else ""
+    value = cell.find(VALUE_TAG)
+    if value is None:
+        return ""
+    raw = text_of(value)
+    if cell_type == "s":
+        try:
+            return shared_strings[int(raw)]
+        except (IndexError, ValueError) as exc:
+            raise CatalogExportError(f"shared string 索引无效: {raw!r}") from exc
+    return raw
+
+
+def worksheet_name(archive: ZipFile) -> str:
+    """选择工作簿的第一个工作表；第三方导出只有一个数据表。"""
+
+    sheets = sorted(
+        name
+        for name in archive.namelist()
+        if name.startswith("xl/worksheets/sheet") and name.endswith(".xml")
+    )
+    if not sheets:
+        raise CatalogExportError("XLSX 中没有工作表")
+    return sheets[0]
+
+
+def iter_rows(path: Path) -> Iterator[tuple[int, list[str]]]:
+    """流式迭代第一个工作表的行，跳过错误的 dimension 元数据。"""
+
+    try:
+        archive = ZipFile(path)
+    except OSError as exc:
+        raise CatalogExportError(f"无法打开工作簿: {path}") from exc
+    with archive:
+        shared_strings = read_shared_strings(archive)
+        with archive.open(worksheet_name(archive)) as worksheet:
+            for _, row in etree.iterparse(worksheet, events=("end",), tag=ROW_TAG):
+                cells: dict[int, str] = {}
+                for cell in row.findall(CELL_TAG):
+                    reference = cell.get("r", "")
+                    if reference:
+                        cells[column_index(reference)] = cell_value(cell, shared_strings)
+                row_number = int(row.get("r", "0"))
+                if cells:
+                    values = ["" for _ in range(max(cells) + 1)]
+                    for index, value in cells.items():
+                        values[index] = value
+                    yield row_number, values
+                row.clear()
+                while row.getprevious() is not None:
+                    del row.getparent()[0]
+
+
+def normalize_header(value: str) -> str:
+    """统一繁简体和空白，便于严格识别来源中的规格列名。"""
+
+    return (
+        value.strip()
+        .lower()
+        .replace(" ", "")
+        .replace("顏", "颜")
+        .replace("色", "色")
+        .replace("分類", "分类")
+        .replace("碼", "码")
+    )
+
+
+def dimension_kind(header: str) -> str:
+    """只依据明确的字段名判断颜色或尺码，其他列不猜测。"""
+
+    normalized = normalize_header(header)
+    if "尺码" in normalized or "尺寸" in normalized:
+        return "size"
+    if "颜色" in normalized:
+        return "color"
+    return ""
+
+
+def value_at(values: list[str], index: int | None) -> str:
+    return values[index].strip() if index is not None and index < len(values) else ""
+
+
+def canonical_pdd(raw_url: str) -> tuple[str, str, str]:
+    """提取 PDD goods_id；失败时返回明确校验码而不是丢弃蝦皮数据。"""
+
+    if not raw_url:
+        return "", "", "PDD_URL_MISSING"
+    parsed = urlparse(raw_url)
+    if parsed.scheme not in {"http", "https"} or parsed.hostname not in PDD_HOSTS:
+        return "", "", "PDD_URL_HOST_INVALID"
+    goods_id = parse_qs(parsed.query).get("goods_id", [""])[0].strip()
+    if not GOODS_ID_PATTERN.fullmatch(goods_id):
+        return "", "", "PDD_GOODS_ID_MISSING"
+    return goods_id, f"https://mobile.yangkeduo.com/goods.html?goods_id={goods_id}", ""
+
+
+def join_spec(first: str, second: str) -> str:
+    """按源列顺序保留规格原文；值内即使有逗号也不拆分。"""
+
+    return ",".join(value for value in (first, second) if value)
+
+
+def build_record(
+    values: list[str],
+    indexes: dict[str, int],
+    source_file: str,
+    row_number: int,
+) -> dict[str, str]:
+    """把来源一行映射成后续商品目录入库所需字段。"""
+
+    first_name = value_at(values, indexes["变种属性名称一"])
+    second_name = value_at(values, indexes["变种属性名称二"])
+    first_value = value_at(values, indexes["变种属性值一"])
+    second_value = value_at(values, indexes["变种属性值二"])
+    color = ""
+    size = ""
+    if dimension_kind(first_name) == "color":
+        color = first_value
+    elif dimension_kind(first_name) == "size":
+        size = first_value
+    if dimension_kind(second_name) == "color":
+        color = second_value
+    elif dimension_kind(second_name) == "size":
+        size = second_value
+    raw_pdd_url = value_at(values, indexes["来源URL"])
+    pdd_goods_id, pdd_goods_url, validation_code = canonical_pdd(raw_pdd_url)
+    shopee_goods_id = value_at(values, indexes["产品id"])
+    if not GOODS_ID_PATTERN.fullmatch(shopee_goods_id):
+        validation_code = ";".join(
+            value for value in (validation_code, "SHOPEE_GOODS_ID_INVALID") if value
+        )
+    parse_ok = bool(color or size)
+    return {
+        "source_file": source_file,
+        "source_row": str(row_number),
+        "source_updated_at": value_at(values, indexes.get("更新时间")),
+        "shopee_goods_id": shopee_goods_id,
+        "shopee_title": value_at(values, indexes["产品标题"]),
+        "shopee_status": "",
+        "shopee_shop_name": value_at(values, indexes["店铺名"]),
+        "shopee_image_url": value_at(values, indexes["主图（URL）地址"]),
+        "shopee_main_sku_code": value_at(values, indexes["Parent SKU"]),
+        "shopee_sku_id": "",
+        "shopee_sku_code": value_at(values, indexes["sku"]),
+        "spec_raw": join_spec(first_value, second_value),
+        "color": color,
+        "size": size,
+        "advice": "",
+        "parse_ok": "true" if parse_ok else "false",
+        "pdd_goods_id": pdd_goods_id,
+        "pdd_goods_url": pdd_goods_url,
+        "pdd_title": "",
+        "pdd_shop_name": "",
+        "association_shopee_goods_id": shopee_goods_id if pdd_goods_id else "",
+        "association_pdd_goods_id": pdd_goods_id,
+        "source_pdd_url": raw_pdd_url,
+        "pdd_importable": "true" if pdd_goods_id else "false",
+        "validation_code": validation_code,
+    }
+
+
+def export_file(source: Path, input_root: Path, output_root: Path) -> ExportResult:
+    """转换一个 XLSX，并以原子替换方式写出对应 CSV。"""
+
+    rows = iter_rows(source)
+    try:
+        _, headers = next(rows)
+    except StopIteration as exc:
+        raise CatalogExportError(f"{source.name} 没有表头") from exc
+    indexes = {header: position for position, header in enumerate(headers) if header}
+    missing = [header for header in REQUIRED_HEADERS if header not in indexes]
+    if missing:
+        raise CatalogExportError(f"{source.name} 缺少列: {', '.join(missing)}")
+
+    relative = source.relative_to(input_root)
+    output = (output_root / relative).with_suffix(".csv")
+    output.parent.mkdir(parents=True, exist_ok=True)
+    validation_counts: Counter[str] = Counter()
+    row_count = 0
+    valid_pdd_rows = 0
+    temp_name = ""
+    try:
+        with NamedTemporaryFile(
+            mode="w", encoding="utf-8-sig", newline="", delete=False, dir=output.parent,
+            prefix=output.stem + ".", suffix=".tmp"
+        ) as temp:
+            temp_name = temp.name
+            writer = csv.DictWriter(temp, fieldnames=CSV_FIELDS, extrasaction="raise")
+            writer.writeheader()
+            for row_number, values in rows:
+                record = build_record(values, indexes, relative.as_posix(), row_number)
+                writer.writerow(record)
+                row_count += 1
+                if record["pdd_importable"] == "true":
+                    valid_pdd_rows += 1
+                if record["validation_code"]:
+                    for code in record["validation_code"].split(";"):
+                        validation_counts[code] += 1
+        Path(temp_name).replace(output)
+    except Exception:
+        if temp_name:
+            Path(temp_name).unlink(missing_ok=True)
+        raise
+    return ExportResult(
+        source=source,
+        output=output,
+        rows=row_count,
+        valid_pdd_rows=valid_pdd_rows,
+        validation_counts=tuple(sorted(validation_counts.items())),
+    )
+
+
+def discover_sources(input_path: Path) -> tuple[Path, Path, list[Path]]:
+    """支持单文件或目录；目录模式保留其下原始相对路径。"""
+
+    if input_path.is_file():
+        if input_path.suffix.lower() != ".xlsx":
+            raise CatalogExportError("输入文件必须是 .xlsx")
+        return input_path, input_path.parent, [input_path]
+    if not input_path.is_dir():
+        raise CatalogExportError(f"找不到输入路径: {input_path}")
+    sources = sorted(path for path in input_path.rglob("*.xlsx") if not path.name.startswith("~$"))
+    if not sources:
+        raise CatalogExportError(f"目录中没有 .xlsx 文件: {input_path}")
+    return input_path, input_path, sources
+
+
+def run(args: argparse.Namespace) -> int:
+    input_path = Path(args.input).resolve()
+    output_root = Path(args.output_dir).resolve()
+    _, input_root, sources = discover_sources(input_path)
+    if output_root == input_root or output_root.is_relative_to(input_root):
+        raise CatalogExportError("输出目录不能位于输入目录内，避免把 CSV 当成后续输入")
+    results = [export_file(source, input_root, output_root) for source in sources]
+    total_rows = sum(result.rows for result in results)
+    total_valid_pdd = sum(result.valid_pdd_rows for result in results)
+    validation_counts: Counter[str] = Counter()
+    for result in results:
+        validation_counts.update(dict(result.validation_counts))
+        print(
+            f"{result.source.name}: {result.rows} 行，PDD 可入库 {result.valid_pdd_rows} 行，"
+            f"输出 {result.output}"
+        )
+    print(f"转换完成：{len(results)} 个 XLSX，{total_rows} 行，PDD 可入库 {total_valid_pdd} 行。")
+    if validation_counts:
+        print("校验提示：" + "，".join(f"{code} {count}" for code, count in sorted(validation_counts.items())))
+    print("本工具未调用接口，也未写入任何数据库。")
+    return 0
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(description="把第三方 ERP XLSX 导出为规范商品目录 CSV")
+    parser.add_argument("input", help="一个 XLSX 文件或包含 XLSX 的目录")
+    parser.add_argument("--output-dir", required=True, help="CSV 输出根目录（必须在输入目录之外）")
+    return parser
+
+
+def main() -> int:
+    try:
+        return run(build_parser().parse_args())
+    except CatalogExportError as exc:
+        print(f"转换失败：{exc}", file=sys.stderr)
+        return 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/tools/requirements-thirdparty-catalog-export.txt b/tools/requirements-thirdparty-catalog-export.txt
new file mode 100644
index 0000000..794d70b
--- /dev/null
+++ b/tools/requirements-thirdparty-catalog-export.txt
@@ -0,0 +1 @@
+lxml==6.1.1
diff --git a/tools/test_export_thirdparty_catalog_xlsx.py b/tools/test_export_thirdparty_catalog_xlsx.py
new file mode 100644
index 0000000..d1a0f57
--- /dev/null
+++ b/tools/test_export_thirdparty_catalog_xlsx.py
@@ -0,0 +1,91 @@
+import csv
+import importlib.util
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+from xml.sax.saxutils import escape
+from zipfile import ZIP_DEFLATED, ZipFile
+
+
+MODULE_PATH = Path(__file__).with_name("export_thirdparty_catalog_xlsx.py")
+SPEC = importlib.util.spec_from_file_location("thirdparty_export", MODULE_PATH)
+assert SPEC and SPEC.loader
+catalog = importlib.util.module_from_spec(SPEC)
+sys.modules[SPEC.name] = catalog
+SPEC.loader.exec_module(catalog)
+
+
+HEADERS = [
+    "Parent SKU", "产品标题", "sku", "变种属性名称一", "变种属性名称二",
+    "变种属性值一", "变种属性值二", "主图（URL）地址", "来源URL", "店铺名",
+    "产品id", "更新时间",
+]
+
+
+def inline_cell(column, row, value):
+    return f'<c r="{column}{row}" t="inlineStr"><is><t>{escape(value)}</t></is></c>'
+
+
+def make_xlsx(path, data_rows):
+    rows = []
+    for row_number, values in enumerate([HEADERS, *data_rows], start=1):
+        cells = "".join(inline_cell(chr(65 + index), row_number, value) for index, value in enumerate(values))
+        rows.append(f'<row r="{row_number}">{cells}</row>')
+    worksheet = (
+        '<?xml version="1.0" encoding="UTF-8"?>'
+        '<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">'
+        '<dimension ref="A1"/><sheetData>' + "".join(rows) + '</sheetData></worksheet>'
+    )
+    with ZipFile(path, "w", ZIP_DEFLATED) as archive:
+        archive.writestr("xl/worksheets/sheet1.xml", worksheet)
+
+
+class ThirdPartyCatalogExportTest(unittest.TestCase):
+    def make_source(self, rows):
+        temp = tempfile.TemporaryDirectory()
+        root = Path(temp.name) / "source"
+        source = root / "pinduoduo 域名" / "sample.xlsx"
+        source.parent.mkdir(parents=True)
+        make_xlsx(source, rows)
+        self.addCleanup(temp.cleanup)
+        return root, source, Path(temp.name) / "output"
+
+    def test_错误_dimension_仍导出完整数据和规范_pdd_url(self):
+        root, source, output = self.make_source([
+            ["MAIN", "标题", "SKU-A", "颜色分类", "尺码", "黑色", "M", "https://img.example/a.jpg", "https://mobile.pinduoduo.com/goods.html?goods_id=123456789&track=1", "店铺 A", "24948397488", "2026-08-19"],
+            ["MAIN", "标题", "SKU-B", "尺碼", "顏色", "L", "白色", "https://img.example/a.jpg", "https://mobile.yangkeduo.com/goods.html?goods_id=987654321", "店铺 A", "24948397488", "2026-08-19"],
+        ])
+        result = catalog.export_file(source, root, output)
+        self.assertEqual((result.rows, result.valid_pdd_rows), (2, 2))
+        with result.output.open(encoding="utf-8-sig", newline="") as handle:
+            exported = list(csv.DictReader(handle))
+        self.assertEqual(len(exported), 2)
+        self.assertEqual(exported[0]["pdd_goods_url"], "https://mobile.yangkeduo.com/goods.html?goods_id=123456789")
+        self.assertEqual((exported[0]["color"], exported[0]["size"], exported[0]["parse_ok"]), ("黑色", "M", "true"))
+        self.assertEqual((exported[1]["color"], exported[1]["size"]), ("白色", "L"))
+        self.assertEqual(exported[0]["source_file"], "pinduoduo 域名/sample.xlsx")
+
+    def test_无效_pdd_url_保留蝦皮字段但不创建关联(self):
+        root, source, output = self.make_source([
+            ["MAIN", "标题", "SKU-A", "款式", "套餐", "甲", "乙", "https://img.example/a.jpg", "https://example.com/item", "店铺 A", "24948397488", ""],
+        ])
+        result = catalog.export_file(source, root, output)
+        self.assertEqual((result.rows, result.valid_pdd_rows), (1, 0))
+        with result.output.open(encoding="utf-8-sig", newline="") as handle:
+            exported = next(csv.DictReader(handle))
+        self.assertEqual(exported["shopee_goods_id"], "24948397488")
+        self.assertEqual(exported["spec_raw"], "甲,乙")
+        self.assertEqual(exported["parse_ok"], "false")
+        self.assertEqual(exported["association_pdd_goods_id"], "")
+        self.assertEqual(exported["validation_code"], "PDD_URL_HOST_INVALID")
+
+    def test_输出目录不能位于输入目录内(self):
+        root, _, _ = self.make_source([])
+        args = catalog.build_parser().parse_args([str(root), "--output-dir", str(root / "csv")])
+        with self.assertRaisesRegex(catalog.CatalogExportError, "输出目录"):
+            catalog.run(args)
+
+
+if __name__ == "__main__":
+    unittest.main()