diff --git a/差旅报销.py b/差旅报销.py
index 4541692..0d3317f 100644
--- a/差旅报销.py
+++ b/差旅报销.py
@@ -14,8 +14,11 @@ import argparse
 import json
 import re
 import shutil
+import zipfile
 from datetime import date
 from pathlib import Path
+from tempfile import NamedTemporaryFile
+from xml.etree import ElementTree as ET
 
 import pdfplumber
 
@@ -306,35 +309,88 @@ def ensure_fill_dependencies():
 
 def fill_template(result, output_dir):
     output_dir.mkdir(exist_ok=True)
-    import openpyxl
 
     meta = result["meta"]
-    expenses = result["expenses"]
     output_file = output_dir / build_output_filename(meta)
 
     shutil.copy(TEMPLATE_FILE, output_file)
-    wb = openpyxl.load_workbook(output_file)
-    ws = wb.active
-
-    ws["E3"] = meta["出差事由"]
-    ws["A6"] = f'{meta["出发日期"]}-{meta["结束日期"]}'
-    ws["B6"] = f'{meta["出发地"]}-{meta["目的地"]}'
-    ws["C6"] = f'{meta["出差天数"]}天'
-    ws["D6"] = meta["出行方式"]
-
-    ws["H6"] = expenses["住宿"]["单据张数"]
-    ws["I6"] = expenses["住宿"]["金额"]
-    ws["H7"] = expenses["饮食"]["单据张数"]
-    ws["I7"] = expenses["饮食"]["金额"]
-    ws["H8"] = expenses["交通"]["单据张数"]
-    ws["I8"] = expenses["交通"]["金额"]
-    ws["H9"] = expenses["其他"]["单据张数"]
-    ws["I9"] = expenses["其他"]["金额"]
-
-    wb.save(output_file)
+    update_xlsx_cells(output_file, build_cell_values(result))
     return output_file
 
 
+def build_cell_values(result):
+    meta = result["meta"]
+    expenses = result["expenses"]
+    return {
+        "E3": meta["出差事由"],
+        "A6": f'{meta["出发日期"]}-{meta["结束日期"]}',
+        "B6": f'{meta["出发地"]}-{meta["目的地"]}',
+        "C6": f'{meta["出差天数"]}天',
+        "D6": meta["出行方式"],
+        "H6": expenses["住宿"]["单据张数"],
+        "I6": expenses["住宿"]["金额"],
+        "H7": expenses["饮食"]["单据张数"],
+        "I7": expenses["饮食"]["金额"],
+        "H8": expenses["交通"]["单据张数"],
+        "I8": expenses["交通"]["金额"],
+        "H9": expenses["其他"]["单据张数"],
+        "I9": expenses["其他"]["金额"],
+    }
+
+
+def update_xlsx_cells(xlsx_path, cell_values):
+    temp_file = NamedTemporaryFile(delete=False, suffix=".xlsx", dir=xlsx_path.parent)
+    temp_path = Path(temp_file.name)
+    temp_file.close()
+
+    try:
+        with zipfile.ZipFile(xlsx_path, "r") as source:
+            with zipfile.ZipFile(temp_path, "w", compression=zipfile.ZIP_DEFLATED) as target:
+                for item in source.infolist():
+                    data = source.read(item.filename)
+                    if item.filename == "xl/worksheets/sheet1.xml":
+                        data = update_sheet_xml(data, cell_values)
+                    target.writestr(item, data)
+        temp_path.replace(xlsx_path)
+    except Exception:
+        temp_path.unlink(missing_ok=True)
+        raise
+
+
+def update_sheet_xml(sheet_xml, cell_values):
+    namespace = "http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+    ET.register_namespace("", namespace)
+    root = ET.fromstring(sheet_xml)
+    for cell_ref, value in cell_values.items():
+        cell = root.find(f".//{{{namespace}}}c[@r='{cell_ref}']")
+        if cell is None:
+            raise SystemExit(f"模板缺少单元格：{cell_ref}")
+        set_cell_xml_value(cell, value, namespace)
+    return ET.tostring(root, encoding="utf-8", xml_declaration=True)
+
+
+def set_cell_xml_value(cell, value, namespace):
+    for child in list(cell):
+        if child.tag in {f"{{{namespace}}}v", f"{{{namespace}}}f", f"{{{namespace}}}is"}:
+            cell.remove(child)
+
+    if isinstance(value, (int, float)):
+        cell.attrib.pop("t", None)
+        value_node = ET.SubElement(cell, f"{{{namespace}}}v")
+        value_node.text = format_number_for_excel(value)
+    else:
+        cell.set("t", "inlineStr")
+        inline_string = ET.SubElement(cell, f"{{{namespace}}}is")
+        text_node = ET.SubElement(inline_string, f"{{{namespace}}}t")
+        text_node.text = str(value)
+
+
+def format_number_for_excel(value):
+    if isinstance(value, int):
+        return str(value)
+    return f"{float(value):.10f}".rstrip("0").rstrip(".")
+
+
 def finalize_archive_dir(archive_dir, result):
     if archive_dir == Path("."):
         return archive_dir
@@ -428,6 +484,37 @@ def verify_output(output_file, result):
         if not isinstance(value, str) or not value.startswith("="):
             raise SystemExit(f"输出校验失败：{label} 单元格 {cell} 公式丢失，当前值={value!r}")
 
+    verify_xlsx_styles_preserved(output_file)
+
+
+def verify_xlsx_styles_preserved(output_file):
+    with zipfile.ZipFile(TEMPLATE_FILE, "r") as template, zipfile.ZipFile(output_file, "r") as output:
+        if template.read("xl/styles.xml") != output.read("xl/styles.xml"):
+            raise SystemExit("输出校验失败：样式表 xl/styles.xml 与模板不一致")
+
+        template_styles = read_sheet_cell_style_ids(template.read("xl/worksheets/sheet1.xml"))
+        output_styles = read_sheet_cell_style_ids(output.read("xl/worksheets/sheet1.xml"))
+        for cell_ref in filled_cell_refs():
+            if template_styles.get(cell_ref) != output_styles.get(cell_ref):
+                raise SystemExit(
+                    f"输出校验失败：单元格 {cell_ref} 样式编号变化，"
+                    f"模板={template_styles.get(cell_ref)!r} 输出={output_styles.get(cell_ref)!r}"
+                )
+
+
+def read_sheet_cell_style_ids(sheet_xml):
+    namespace = "http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+    root = ET.fromstring(sheet_xml)
+    return {
+        cell.attrib["r"]: cell.attrib.get("s")
+        for cell in root.findall(f".//{{{namespace}}}c")
+        if "r" in cell.attrib
+    }
+
+
+def filled_cell_refs():
+    return ["E3", "A6", "B6", "C6", "D6", "H6", "I6", "H7", "I7", "H8", "I8", "H9", "I9"]
+
 
 def build_parser():
     parser = argparse.ArgumentParser(description="差旅报销自动化脚本")