diff --git a/lib/Projectrans/DeclarationGenerator.py b/lib/Projectrans/DeclarationGenerator.py
index 4918840..12ffba7 100644
--- a/lib/Projectrans/DeclarationGenerator.py
+++ b/lib/Projectrans/DeclarationGenerator.py
@@ -10,7 +10,7 @@ import llvmlite.ir as ir
 from lib.core import TypeSystem
 from lib.core.TypeSystem import CTypeRegistry
 from lib.core.SymbolUtils import (
-    IsListAnnotation, AnnotationContainsName, IsCPtrSubscriptNode, IsCPtrNode,
+    IsListAnnotation, AnnotationContainsName, RejectTypeUnion, IsCPtrSubscriptNode, IsCPtrNode,
     IsRawPtrSubscriptNode, IsPtrSubscriptNode, ResolveGenericTypeArgStr,
     EnumClassIntWidth, ClassHasFuncLevelCVTable)
 
@@ -1187,6 +1187,8 @@ class DeclarationGenerator:
         if annotation is None:
             return 'i8*'
 
+        RejectTypeUnion(annotation)
+
         non_struct_types: set[str] = {'list', 'dict', 'tuple', 'set', 'array', 'CArray', 'rawarray'}
 
         if isinstance(annotation, ast.Name):
diff --git a/lib/core/Handles/HandlesTypeMerge.py b/lib/core/Handles/HandlesTypeMerge.py
index 36562cc..746ef0f 100644
--- a/lib/core/Handles/HandlesTypeMerge.py
+++ b/lib/core/Handles/HandlesTypeMerge.py
@@ -5,7 +5,7 @@ if TYPE_CHECKING:
 from typing import List
 from lib.core.Handles.HandlesBase import BaseHandle, CTypeHelper, CTypeInfo
 from lib.core.SymbolUtils import (
-    IsListAnnotation, IsPtrSubscriptNode, IsCPtrMarkerNode,
+    IsListAnnotation, IsPtrSubscriptNode, IsCPtrMarkerNode, RejectTypeUnion,
     DesugarPtrSubscriptToUnion)
 from lib.core import TypeSystem
 import lib._bootstrap  # noqa: F401  设置 sys.path（项目根 + lib）
@@ -27,6 +27,7 @@ class HandlesTypeMerge(BaseHandle):
 
     def GetCTypeInfo(self, Node: ast.AST) -> CTypeInfo:
         """获取 CTypeInfo 对象"""
+        RejectTypeUnion(Node)
         Result = self._GetCTypeInfoInternal(Node)
         if isinstance(Result, CTypeInfo):
             return Result
diff --git a/lib/core/LLVMTypeMapper.py b/lib/core/LLVMTypeMapper.py
index 13d428e..93ce774 100644
--- a/lib/core/LLVMTypeMapper.py
+++ b/lib/core/LLVMTypeMapper.py
@@ -19,7 +19,7 @@ if TYPE_CHECKING:
 
 from lib.core.Handles.HandlesBase import CTypeInfo, CTypeHelper, BuiltinTypeMap
 from lib.core.SymbolUtils import (
-    IsListAnnotation, IsCPtrNode, IsCPtrSubscriptNode,
+    IsListAnnotation, RejectTypeUnion, IsCPtrNode, IsCPtrSubscriptNode,
     IsRawPtrSubscriptNode, EnumIntWidth,
     ResolveGenericClassSpecName, GetStructSha1MapFromSymtab, GetTCAliasMapFromSymtab)
 from lib.core import TypeSystem as _t
@@ -121,6 +121,7 @@ class LLVMTypeMapper:
         if node is None:
             self._symtab.diagnostics.warn('', 0, "类型注解为 None，回退到 i32")
             return 'i32'
+        RejectTypeUnion(node)
         if isinstance(node, ast.Name):
             return self._resolve_name(node)
         elif isinstance(node, ast.Attribute):
diff --git a/lib/core/SymbolUtils.py b/lib/core/SymbolUtils.py
index 43a73a8..d2491ae 100644
--- a/lib/core/SymbolUtils.py
+++ b/lib/core/SymbolUtils.py
@@ -2160,6 +2160,51 @@ def RequireNameDefined(Gen: object, Trans: object, Node: object, Name: str) -> N
     )
 
 
+# 类型注解中允许出现在 `|` 一侧的内建修饰标记。除此之外的任何 `T1 | T2`
+# 都视为「类型联合」并直接拒绝：类型注解只能是单一类型。
+_UNION_MARKER_NAMES: frozenset[str] = frozenset({
+    'CConst', 'CVolatile', 'CExport', 'CExtern', 'CStatic', 'CInline', 'State',
+    'CDefine', 'CTypedef', 'CPtr', 'CArrayPtr', 'CAutoPtr', 'CRef', 'CTempRef',
+    'BigEndian', 'LittleEndian', 'Bit',
+})
+
+
+def _IsUnionMarkerNode(node: ast.AST) -> bool:
+    """节点是否为内建修饰标记（裸名、attr.* 或带调用括号的标记）。"""
+    if isinstance(node, ast.Name):
+        return node.id in _UNION_MARKER_NAMES
+    if isinstance(node, ast.Attribute):
+        cur: ast.AST = node
+        while isinstance(cur, ast.Attribute):
+            cur = cur.value
+        return isinstance(cur, ast.Name) and cur.id == 'attr'
+    if isinstance(node, ast.Call):
+        return _IsUnionMarkerNode(node.func)
+    return False
+
+
+def _ContainsUnionMarker(node: ast.AST) -> bool:
+    if _IsUnionMarkerNode(node):
+        return True
+    if isinstance(node, ast.BinOp) and isinstance(node.op, ast.BitOr):
+        return _ContainsUnionMarker(node.left) or _ContainsUnionMarker(node.right)
+    return False
+
+
+def RejectTypeUnion(Annotation: ast.AST | None) -> None:
+    """拒绝 `T1 | T2` 类型联合；只允许「单一类型 | 内建修饰标记」。"""
+    if not (isinstance(Annotation, ast.BinOp) and isinstance(Annotation.op, ast.BitOr)):
+        return
+    if _ContainsUnionMarker(Annotation):
+        return
+    Line: int = getattr(Annotation, 'lineno', 0) or 0
+    raise TypeError(
+        f"[TPC] 不支持类型联合 'T1 | T2'（第 {Line} 行）。"
+        f"类型注解只能是单一类型：指针请写 CPtr[T] / rawptr[T]；"
+        f"const / volatile / static / export / extern 请使用对应关键字。"
+    )
+
+
 def AnnotationContainsMarker(node: ast.AST, MarkerName: str) -> bool:
     """注解 AST 中是否出现指定内建标记名（裸名，或属性形态的尾名）。"""
     if isinstance(node, ast.Name):
diff --git a/lib/core/TypeAnnotationResolver.py b/lib/core/TypeAnnotationResolver.py
index 92fa6de..750a428 100644
--- a/lib/core/TypeAnnotationResolver.py
+++ b/lib/core/TypeAnnotationResolver.py
@@ -9,7 +9,7 @@ from typing import TYPE_CHECKING
 from lib.core.Handles.HandlesBase import CTypeInfo, BuiltinTypeMap, CTypeHelper
 from lib.core.ConstEvaluator import ConstEvaluator
 from lib.core.SymbolUtils import (
-    IsListAnnotation,
+    IsListAnnotation, RejectTypeUnion,
     ResolveGenericClassSpecName, GetStructSha1MapFromSymtab, GetTCAliasMapFromSymtab)
 from lib.core import TypeSystem
 from lib.constants.config import mode as _config_mode
@@ -91,6 +91,7 @@ class TypeAnnotationResolver:
             Node: AST 节点（如 ast.Name, ast.Attribute 等）
             SymbolTable: 符号表字典
         """
+        RejectTypeUnion(Node)
         if isinstance(Node, ast.Constant):
             return TypeAnnotationResolver._from_node_constant(Node, SymbolTable)
         if isinstance(Node, ast.Name):