diff --git a/README.md b/README.md
index 76dbc46..94bd364 100644
--- a/README.md
+++ b/README.md
@@ -102,6 +102,7 @@ cookies 保存到 `session.json`（与 exe 同目录）。登录成功后自动
 | 寄达地区划代码 | 直接决定寄达地，勾选强制覆盖后优先级最高 |
 | 寄件人姓名 | 强制覆盖客户资料中的寄件人 |
 | 寄件地址 | 强制覆盖客户资料中的寄件地址 |
+| 长 / 宽 / 高 | 有值即强制覆盖提交表单中的包裹尺寸 |
 
 ### 5. 开始处理
 
@@ -136,6 +137,7 @@ cookies 保存到 `session.json`（与 exe 同目录）。登录成功后自动
 "字段名": {"value": "值", "force": false}
 ```
 `force: true` 时覆盖 API 获取值。GUI 中通过复选框控制，点击"开始处理"时自动保存到配置文件。
+长、宽、高在 GUI 中填写后会自动保存为强制固定值；留空时不覆盖 Excel 或系统已有值。
 
 ### defaults
 字段的默认值（中文名，自动翻译为系统编码）。
diff --git a/config.json b/config.json
index 71a8a7b..7dc482c 100644
--- a/config.json
+++ b/config.json
@@ -20,7 +20,10 @@
         "寄达地": {"value": "", "force": false},
         "寄达地区划": {"value": "", "force": false},
         "产品名称": {"value": "", "force": false},
-        "内件品名": {"value": "", "force": false}
+        "内件品名": {"value": "", "force": false},
+        "长": {"value": "", "force": false},
+        "宽": {"value": "", "force": false},
+        "高": {"value": "", "force": false}
     },
     "defaults": {
         "电商平台": "无",
@@ -34,4 +37,4 @@
         "代收标志": "不代收",
         "投递方式": "普通投递"
     }
-}
\ No newline at end of file
+}
diff --git a/field_mapping.py b/field_mapping.py
index f3aff05..c403ca8 100644
--- a/field_mapping.py
+++ b/field_mapping.py
@@ -29,6 +29,9 @@ BUILTIN_FIELD_MAP: dict[str, str] = {
     "寄件人固话": "senderFixtel",
     # ── 货物 ──
     "重量": "realWeight",
+    "长": "length",
+    "宽": "width",
+    "高": "height",
     "内件品名": "reserved5",
     # ── 电商 / 支付 ──
     "电商平台": "ecommerceNo",
diff --git a/main.py b/main.py
index 881f629..0ebf212 100644
--- a/main.py
+++ b/main.py
@@ -125,6 +125,9 @@ class App:
         self.fv_sender_addr = StringVar()
         self.fv_transport_type = StringVar()
         self.fv_weight = StringVar()
+        self.fv_length = StringVar()
+        self.fv_width = StringVar()
+        self.fv_height = StringVar()
 
         # 搜索基础设施（懒加载）
         self._search_bridge = None
@@ -244,7 +247,19 @@ class App:
         Entry(r1, textvariable=self.fv_weight, width=10).pack(side="left", padx=5)
         Label(r1, text="（有值即强制覆盖）", fg="gray", font=("", 8)).pack(side="left")
 
-        # Row 2: 寄达地 | 寄达地区划代码
+        # Row 2: 长 | 宽 | 高
+        r_dimensions = Frame(fixed_frame)
+        r_dimensions.pack(fill=X, pady=2)
+        for label, variable in (
+            ("长:", self.fv_length),
+            ("宽:", self.fv_width),
+            ("高:", self.fv_height),
+        ):
+            Label(r_dimensions, text=label, width=5, anchor="e").pack(side="left")
+            Entry(r_dimensions, textvariable=variable, width=10).pack(side="left", padx=5)
+        Label(r_dimensions, text="（有值即强制覆盖）", fg="gray", font=("", 8)).pack(side="left")
+
+        # Row 3: 寄达地 | 寄达地区划代码
         r2 = Frame(fixed_frame)
         r2.pack(fill=X, pady=2)
         Label(r2, text="寄达地:", width=10, anchor="e").pack(side="left")
@@ -256,7 +271,7 @@ class App:
         self.fv_district_combo.pack(side="left", padx=5)
         Checkbutton(r2, text="强制覆盖", variable=self.fv_force_district).pack(side="left", padx=2)
 
-        # Row 3: 寄件人姓名 | 寄件地址
+        # Row 4: 寄件人姓名 | 寄件地址
         r3 = Frame(fixed_frame)
         r3.pack(fill=X, pady=2)
         Label(r3, text="寄件人姓名:", width=10, anchor="e").pack(side="left")
@@ -380,6 +395,9 @@ class App:
             self.fv_sender_name.set(fv.get("寄件人", {}).get("value", ""))
             self.fv_sender_addr.set(fv.get("寄件地址", {}).get("value", ""))
             self.fv_weight.set(fv.get("重量", {}).get("value", ""))
+            self.fv_length.set(fv.get("长", {}).get("value", ""))
+            self.fv_width.set(fv.get("宽", {}).get("value", ""))
+            self.fv_height.set(fv.get("高", {}).get("value", ""))
 
             # 加载区划代码下拉选项
             dc = self.config.get("district_codes", {})
@@ -418,6 +436,9 @@ class App:
         sender_val = self.fv_sender_name.get().strip()
         addr_val = self.fv_sender_addr.get().strip()
         weight_val = self.fv_weight.get().strip()
+        length_val = self.fv_length.get().strip()
+        width_val = self.fv_width.get().strip()
+        height_val = self.fv_height.get().strip()
         # 区划代码：Combobox 显示中文名，实际存 propertyCode
         dist_name = self.fv_district_code.get()
         dist_code = self._district_codes.get(dist_name, dist_name) if self._district_codes else dist_name
@@ -430,6 +451,9 @@ class App:
             "寄件人": {"value": sender_val, "force": bool(sender_val)},
             "寄件地址": {"value": addr_val, "force": bool(addr_val)},
             "重量": {"value": weight_val, "force": bool(weight_val)},
+            "长": {"value": length_val, "force": bool(length_val)},
+            "宽": {"value": width_val, "force": bool(width_val)},
+            "高": {"value": height_val, "force": bool(height_val)},
         }
         self.config["fixed_values"] = new_fixed
 
@@ -934,6 +958,9 @@ class App:
         self.fv_sender_addr.set("")
         self.fv_transport_type.set("")
         self.fv_weight.set("")
+        self.fv_length.set("")
+        self.fv_width.set("")
+        self.fv_height.set("")
         self._product_cached_choice = None
         self._product_cached_detail = None
         self._customer_cached_choice = None