diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/config_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/config_vo.py
index 5b2745d7e..d7d8e0b1e 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/config_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/config_vo.py
@@ -41,10 +41,15 @@ def get_config_name(self) -> str | None:
     def get_config_value(self) -> str | None:
         return self.config_value
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_config_key()
         self.get_config_name()
         self.get_config_value()
+        self.get_remark()
 
 
 class ConfigQueryModel(DateRangeQueryMixin, ConfigModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/dict_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/dict_vo.py
index ec164c69d..61df92acf 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/dict_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/dict_vo.py
@@ -40,9 +40,14 @@ def get_dict_name(self) -> str | None:
     def get_dict_type(self) -> str | None:
         return self.dict_type
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_dict_name()
         self.get_dict_type()
+        self.get_remark()
 
 
 class DictDataModel(BaseModel):
@@ -86,11 +91,16 @@ def get_dict_type(self) -> str | None:
     def get_css_class(self) -> str | None:
         return self.css_class
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_dict_label()
         self.get_dict_value()
         self.get_dict_type()
         self.get_css_class()
+        self.get_remark()
 
 
 class DictTypeQueryModel(DateRangeQueryMixin, DictTypeModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/job_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/job_vo.py
index db77f30ce..329eefe54 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/job_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/job_vo.py
@@ -112,9 +112,14 @@ def get_invoke_target(self) -> str | None:
     def get_cron_expression(self) -> str | None:
         return self.cron_expression
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_invoke_target()
         self.get_cron_expression()
+        self.get_remark()
 
 
 class JobPreviewRequest(BaseModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/menu_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/menu_vo.py
index ccb63783d..80d427ca3 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/menu_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/menu_vo.py
@@ -61,6 +61,10 @@ def get_menu_type(self) -> Literal['M', 'C', 'F'] | None:
     def get_perms(self) -> str | None:
         return self.perms
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_menu_name()
         self.get_order_num()
@@ -68,6 +72,7 @@ def validate_fields(self) -> None:
         self.get_component()
         self.get_menu_type()
         self.get_perms()
+        self.get_remark()
 
 
 class MenuQueryModel(DateRangeQueryMixin, MenuModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/notice_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/notice_vo.py
index 055ffb54f..9fec9dd4a 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/notice_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/notice_vo.py
@@ -32,8 +32,13 @@ class NoticeModel(BaseModel):
     def get_notice_title(self) -> str | None:
         return self.notice_title
 
+    @Size(field_name='remark', min_length=0, max_length=255, message='备注长度不能超过255个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_notice_title()
+        self.get_remark()
 
 
 class NoticeQueryModel(DateRangeQueryMixin, NoticeModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/post_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/post_vo.py
index 61b900bd9..e7ebfd5b4 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/post_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/post_vo.py
@@ -40,10 +40,15 @@ def get_post_name(self) -> str | None:
     def get_post_sort(self) -> int | None:
         return self.post_sort
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_post_code()
         self.get_post_name()
         self.get_post_sort()
+        self.get_remark()
 
 
 class PostQueryModel(DateRangeQueryMixin, PostModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/role_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/role_vo.py
index c711bc492..6c9906313 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/role_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/role_vo.py
@@ -69,10 +69,15 @@ def get_role_key(self) -> str | None:
     def get_role_sort(self) -> int | None:
         return self.role_sort
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_role_name()
         self.get_role_key()
         self.get_role_sort()
+        self.get_remark()
 
 
 class RoleMenuModel(BaseModel):
diff --git a/ruoyi-fastapi-backend/module_admin/entity/vo/user_vo.py b/ruoyi-fastapi-backend/module_admin/entity/vo/user_vo.py
index f3abc7155..d5bfc348c 100644
--- a/ruoyi-fastapi-backend/module_admin/entity/vo/user_vo.py
+++ b/ruoyi-fastapi-backend/module_admin/entity/vo/user_vo.py
@@ -98,11 +98,16 @@ def get_email(self) -> str | None:
     def get_phonenumber(self) -> str | None:
         return self.phonenumber
 
+    @Size(field_name='remark', min_length=0, max_length=500, message='备注长度不能超过500个字符')
+    def get_remark(self) -> str | None:
+        return self.remark
+
     def validate_fields(self) -> None:
         self.get_user_name()
         self.get_nick_name()
         self.get_email()
         self.get_phonenumber()
+        self.get_remark()
 
 
 class UserRowModel(UserModel):
diff --git a/ruoyi-fastapi-backend/tests/module_admin/entity/test_vo_remark_length.py b/ruoyi-fastapi-backend/tests/module_admin/entity/test_vo_remark_length.py
new file mode 100644
index 000000000..4d2582ef9
--- /dev/null
+++ b/ruoyi-fastapi-backend/tests/module_admin/entity/test_vo_remark_length.py
@@ -0,0 +1,66 @@
+"""备注字段长度校验测试。
+
+备注列在各表中的真实长度来自 sql/ruoyi-fastapi-pg.sql：
+sys_notice.remark 为 varchar(255)，其余业务表的 remark 为 varchar(500)。
+超长备注在写库前必须被拦截，否则会在数据库层报错或（MySQL 非严格模式下）被静默截断。
+"""
+
+import pytest
+from pydantic_validation_decorator import FieldValidationError
+
+from module_admin.entity.vo.config_vo import ConfigModel
+from module_admin.entity.vo.dict_vo import DictDataModel, DictTypeModel
+from module_admin.entity.vo.job_vo import JobModel
+from module_admin.entity.vo.menu_vo import MenuModel
+from module_admin.entity.vo.notice_vo import NoticeModel
+from module_admin.entity.vo.post_vo import PostModel
+from module_admin.entity.vo.role_vo import RoleModel
+from module_admin.entity.vo.user_vo import UserModel
+
+# (模型, remark 列长度)
+REMARK_LENGTH_CASES = [
+    (UserModel, 500),
+    (RoleModel, 500),
+    (PostModel, 500),
+    (MenuModel, 500),
+    (ConfigModel, 500),
+    (DictTypeModel, 500),
+    (DictDataModel, 500),
+    (JobModel, 500),
+    (NoticeModel, 255),
+]
+
+
+class TestRemarkLengthValidation:
+    """备注字段长度校验。"""
+
+    @pytest.mark.parametrize(('model', 'max_length'), REMARK_LENGTH_CASES)
+    def test_remark_at_the_column_limit_is_accepted(self, model: type, max_length: int) -> None:
+        instance = model(remark='备' * max_length)
+
+        instance.get_remark()
+
+        assert len(instance.remark) == max_length
+
+    @pytest.mark.parametrize(('model', 'max_length'), REMARK_LENGTH_CASES)
+    def test_remark_one_past_the_column_limit_is_rejected(self, model: type, max_length: int) -> None:
+        instance = model(remark='备' * (max_length + 1))
+
+        with pytest.raises(FieldValidationError):
+            instance.get_remark()
+
+    @pytest.mark.parametrize(('model', 'max_length'), REMARK_LENGTH_CASES)
+    def test_remark_is_optional(self, model: type, max_length: int) -> None:
+        instance = model(remark=None)
+
+        instance.get_remark()
+
+        assert instance.remark is None
+
+    @pytest.mark.parametrize(('model', 'max_length'), REMARK_LENGTH_CASES)
+    def test_validate_fields_covers_remark(self, model: type, max_length: int) -> None:
+        """validate_fields 是服务层实际调用的入口，它必须覆盖备注字段。"""
+        instance = model(remark='备' * (max_length + 1))
+
+        with pytest.raises(FieldValidationError):
+            instance.validate_fields()