diff --git a/deploy/sql/migrations/cn/baiyue_firstleg/V2__align_measurement_and_fee_schema.sql b/deploy/sql/migrations/cn/baiyue_firstleg/V2__align_measurement_and_fee_schema.sql
index b207b75e1..80b27fb3f 100644
--- a/deploy/sql/migrations/cn/baiyue_firstleg/V2__align_measurement_and_fee_schema.sql
+++ b/deploy/sql/migrations/cn/baiyue_firstleg/V2__align_measurement_and_fee_schema.sql
@@ -1,15 +1,14 @@
 -- Region: CN
 -- Schema: baiyue_firstleg
 -- Purpose: 对齐墨家测量收件箱字段并允许人工报价费用快照缺少船司价格。
--- Preconditions: 连接必须指向 baiyue_firstleg；若墨家收件箱已有记录，必须先完成经批准的重量回填方案；本文件不执行 UPDATE。
+-- Preconditions: 连接必须指向 baiyue_firstleg；墨家收件表已存在；未收到的设备重量保留 NULL，不回填为 0。
 -- Postconditions: 墨家收件箱字段、入库费用船司价格字段与当前 Firstleg 基线一致。
 
 SET NAMES utf8mb4;
 
 SET @guard = IF(
-  EXISTS (SELECT 1 FROM information_schema.tables WHERE table_schema = DATABASE() AND table_name = 'fl_mojia_measurement_receipt')
-  AND EXISTS (SELECT 1 FROM fl_mojia_measurement_receipt LIMIT 1),
-  'SELECT 1 FROM migration_blocked_firstleg_mojia_receipt_requires_weight_review',
+  NOT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_schema = DATABASE() AND table_name = 'fl_mojia_measurement_receipt'),
+  'SELECT 1 FROM migration_blocked_firstleg_mojia_receipt_table_missing',
   'SELECT 1'
 );
 PREPARE stmt FROM @guard; EXECUTE stmt; DEALLOCATE PREPARE stmt;
@@ -21,7 +20,10 @@ SET @ddl = IF(NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_s
   'ALTER TABLE fl_mojia_measurement_receipt ADD COLUMN measurement_kind VARCHAR(16) NOT NULL DEFAULT ''BOX_LABEL'' COMMENT ''测量分流：BOX_LABEL箱唛；SKU一件代发SKU'' AFTER inbound_code', 'SELECT 1');
 PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;
 SET @ddl = IF(NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'fl_mojia_measurement_receipt' AND column_name = 'weight_kg'),
-  'ALTER TABLE fl_mojia_measurement_receipt ADD COLUMN weight_kg DECIMAL(18,3) NOT NULL COMMENT ''设备实测重量kg'' AFTER height_cm', 'SELECT 1');
+  'ALTER TABLE fl_mojia_measurement_receipt ADD COLUMN weight_kg DECIMAL(18,3) NULL COMMENT ''设备实测重量kg；未收到时为空，不以0代替'' AFTER height_cm', 'SELECT 1');
+PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;
+SET @ddl = IF(EXISTS (SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'fl_mojia_measurement_receipt' AND column_name = 'weight_kg' AND is_nullable = 'NO'),
+  'ALTER TABLE fl_mojia_measurement_receipt MODIFY COLUMN weight_kg DECIMAL(18,3) NULL COMMENT ''设备实测重量kg；未收到时为空，不以0代替''', 'SELECT 1');
 PREPARE stmt FROM @ddl; EXECUTE stmt; DEALLOCATE PREPARE stmt;
 SET @ddl = IF(NOT EXISTS (SELECT 1 FROM information_schema.columns WHERE table_schema = DATABASE() AND table_name = 'fl_mojia_measurement_receipt' AND column_name = 'sync_status'),
   'ALTER TABLE fl_mojia_measurement_receipt ADD COLUMN sync_status VARCHAR(24) NULL COMMENT ''SKU同步状态：PENDING/SYNCING/SUCCESS/FAILED'' AFTER status', 'SELECT 1');
diff --git a/deploy/sql/头程数据库统一增量-MySQL8.sql b/deploy/sql/头程数据库统一增量-MySQL8.sql
index 4dcf76941..c7ffeb09f 100644
--- a/deploy/sql/头程数据库统一增量-MySQL8.sql
+++ b/deploy/sql/头程数据库统一增量-MySQL8.sql
@@ -3436,7 +3436,7 @@ CREATE TABLE fl_mojia_measurement_receipt (
   length_cm decimal(12,3) NOT NULL COMMENT '设备实测长度cm',
   width_cm decimal(12,3) NOT NULL COMMENT '设备实测宽度cm',
   height_cm decimal(12,3) NOT NULL COMMENT '设备实测高度cm',
-  weight_kg decimal(18,3) NOT NULL COMMENT '设备实测重量kg',
+  weight_kg decimal(18,3) DEFAULT NULL COMMENT '设备实测重量kg；未收到时为空，不以0代替',
   machine_no varchar(64) NOT NULL COMMENT '设备编号',
   measured_at datetime(3) NOT NULL COMMENT '设备测量时间或服务接收时间',
   image_file_id bigint unsigned NOT NULL COMMENT 'File服务中的墨家联调图片ID',
diff --git a/firstleg/src/main/resources/db/phase2-inbound-schema.sql b/firstleg/src/main/resources/db/phase2-inbound-schema.sql
index 2afc054aa..56fb62383 100644
--- a/firstleg/src/main/resources/db/phase2-inbound-schema.sql
+++ b/firstleg/src/main/resources/db/phase2-inbound-schema.sql
@@ -335,7 +335,7 @@ CREATE TABLE IF NOT EXISTS fl_mojia_measurement_receipt (
   length_cm DECIMAL(12,3) NOT NULL COMMENT '设备实测长度cm',
   width_cm DECIMAL(12,3) NOT NULL COMMENT '设备实测宽度cm',
   height_cm DECIMAL(12,3) NOT NULL COMMENT '设备实测高度cm',
-  weight_kg DECIMAL(18,3) NOT NULL COMMENT '设备实测重量kg',
+  weight_kg DECIMAL(18,3) NULL COMMENT '设备实测重量kg；未收到时为空，不以0代替',
   machine_no VARCHAR(64) NOT NULL COMMENT '设备编号',
   measured_at DATETIME(3) NOT NULL COMMENT '设备测量时间或服务接收时间',
   image_file_id BIGINT UNSIGNED NOT NULL COMMENT 'File服务中的墨家联调图片ID',
diff --git a/scripts/admin-test-env-modules/initialization-baseline-contract.test.mjs b/scripts/admin-test-env-modules/initialization-baseline-contract.test.mjs
index 9f67e26ef..8de5b7f41 100644
--- a/scripts/admin-test-env-modules/initialization-baseline-contract.test.mjs
+++ b/scripts/admin-test-env-modules/initialization-baseline-contract.test.mjs
@@ -89,7 +89,7 @@ test('近期头程与海外结构完整进入各自统一初始化入口', () =>
   const receipt = table(cn, 'baiyue_firstleg', 'fl_mojia_measurement_receipt')
   for (const field of ['measurement_kind', 'weight_kg', 'sync_status', 'sync_failure_code',
     'sync_failure_reason', 'lingxing_sku_id', 'revision']) assert.match(receipt, new RegExp(`\\b${field}\\b`, 'i'))
-  assert.match(receipt, /weight_kg decimal\(18,3\) NOT NULL/i)
+  assert.match(receipt, /weight_kg decimal\(18,3\) DEFAULT NULL/i)
 
   const relabel = table(overseas, 'baiyue_lastleg', 'll_relabel_application')
   assert.match(relabel, /KEY idx_ll_relabel_application_order \(lastleg_order_id\)/i)