diff --git a/ast_checker/engines/__init__.py b/ast_checker/engines/__init__.py
new file mode 100644
index 0000000..9b88312
--- /dev/null
+++ b/ast_checker/engines/__init__.py
@@ -0,0 +1,21 @@
+from .function_call import CountFunctionCallEngine, MustCallFunctionEngine, MustNotCallFunctionEngine
+from .method_call import MustCallMethodEngine, MustNotCallMethodEngine
+from .node_count import CountNodeEngine
+from .node_exists import MustExistNodeEngine, MustNotExistNodeEngine
+from .operator import MustUseOperatorEngine
+
+ENGINES = {
+    "must_exist_node": MustExistNodeEngine(),
+    "must_not_exist_node": MustNotExistNodeEngine(),
+    "count_node": CountNodeEngine(),
+    "must_call_function": MustCallFunctionEngine(),
+    "must_not_call_function": MustNotCallFunctionEngine(),
+    "count_function_call": CountFunctionCallEngine(),
+    "must_call_method": MustCallMethodEngine(),
+    "must_not_call_method": MustNotCallMethodEngine(),
+    "must_use_operator": MustUseOperatorEngine(),
+}
+
+
+def get_engine(name: str):
+    return ENGINES.get(name)
diff --git a/ast_checker/engines/base.py b/ast_checker/engines/base.py
new file mode 100644
index 0000000..3b28da8
--- /dev/null
+++ b/ast_checker/engines/base.py
@@ -0,0 +1,18 @@
+class BaseEngine:
+    @staticmethod
+    def collect_nodes(node, node_type):
+        results = []
+        if node.type == node_type:
+            results.append(node)
+        for child in node.children:
+            results.extend(BaseEngine.collect_nodes(child, node_type))
+        return results
+
+    @staticmethod
+    def has_node(node, node_type):
+        if node.type == node_type:
+            return True
+        return any(BaseEngine.has_node(child, node_type) for child in node.children)
+
+    def check(self, tree, rule, language, mapping) -> list[str]:
+        raise NotImplementedError
diff --git a/ast_checker/engines/function_call.py b/ast_checker/engines/function_call.py
new file mode 100644
index 0000000..d77ce1a
--- /dev/null
+++ b/ast_checker/engines/function_call.py
@@ -0,0 +1,47 @@
+from .base import BaseEngine
+
+CALL_NODE_TYPES = {
+    "Python3": "call",
+    "C": "call_expression",
+}
+
+
+class _FunctionCallBase(BaseEngine):
+    def _find_function_calls(self, root, func_name, language):
+        call_type = CALL_NODE_TYPES.get(language, "call")
+        calls = self.collect_nodes(root, call_type)
+        matches = []
+        for call in calls:
+            func_node = call.child_by_field_name("function")
+            if func_node and func_node.type == "identifier" and func_node.text.decode() == func_name:
+                matches.append(call)
+        return matches
+
+
+class MustCallFunctionEngine(_FunctionCallBase):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        if not self._find_function_calls(tree.root_node, target, language):
+            return [rule.get("message", f"必须调用 {target}()")]
+        return []
+
+
+class MustNotCallFunctionEngine(_FunctionCallBase):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        if self._find_function_calls(tree.root_node, target, language):
+            return [rule.get("message", f"不能调用 {target}()")]
+        return []
+
+
+class CountFunctionCallEngine(_FunctionCallBase):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        count = len(self._find_function_calls(tree.root_node, target, language))
+        min_count = rule.get("min")
+        max_count = rule.get("max")
+        if min_count is not None and count < min_count:
+            return [rule.get("message", f"{target}() 至少调用 {min_count} 次，当前 {count} 次")]
+        if max_count is not None and count > max_count:
+            return [rule.get("message", f"{target}() 至多调用 {max_count} 次，当前 {count} 次")]
+        return []
diff --git a/ast_checker/engines/method_call.py b/ast_checker/engines/method_call.py
new file mode 100644
index 0000000..0dfd3c8
--- /dev/null
+++ b/ast_checker/engines/method_call.py
@@ -0,0 +1,38 @@
+from .base import BaseEngine
+
+CALL_NODE_TYPES = {
+    "Python3": "call",
+    "C": "call_expression",
+}
+
+
+class _MethodCallBase(BaseEngine):
+    def _find_method_calls(self, root, method_name, language):
+        if language == "C":
+            return []
+        call_type = CALL_NODE_TYPES.get(language, "call")
+        calls = self.collect_nodes(root, call_type)
+        matches = []
+        for call in calls:
+            func_node = call.child_by_field_name("function")
+            if func_node and func_node.type == "attribute":
+                attr_node = func_node.child_by_field_name("attribute")
+                if attr_node and attr_node.text.decode() == method_name:
+                    matches.append(call)
+        return matches
+
+
+class MustCallMethodEngine(_MethodCallBase):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        if not self._find_method_calls(tree.root_node, target, language):
+            return [rule.get("message", f"必须调用 .{target}()")]
+        return []
+
+
+class MustNotCallMethodEngine(_MethodCallBase):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        if self._find_method_calls(tree.root_node, target, language):
+            return [rule.get("message", f"不能调用 .{target}()")]
+        return []
diff --git a/ast_checker/engines/node_count.py b/ast_checker/engines/node_count.py
new file mode 100644
index 0000000..6b9b6db
--- /dev/null
+++ b/ast_checker/engines/node_count.py
@@ -0,0 +1,16 @@
+from .base import BaseEngine
+
+
+class CountNodeEngine(BaseEngine):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        node_type = mapping.get(target, target)
+        nodes = self.collect_nodes(tree.root_node, node_type)
+        count = len(nodes)
+        min_count = rule.get("min")
+        max_count = rule.get("max")
+        if min_count is not None and count < min_count:
+            return [rule.get("message", f"{target} 至少出现 {min_count} 次，当前 {count} 次")]
+        if max_count is not None and count > max_count:
+            return [rule.get("message", f"{target} 至多出现 {max_count} 次，当前 {count} 次")]
+        return []
diff --git a/ast_checker/engines/node_exists.py b/ast_checker/engines/node_exists.py
new file mode 100644
index 0000000..b2f1b0f
--- /dev/null
+++ b/ast_checker/engines/node_exists.py
@@ -0,0 +1,19 @@
+from .base import BaseEngine
+
+
+class MustExistNodeEngine(BaseEngine):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        node_type = mapping.get(target, target)
+        if not self.has_node(tree.root_node, node_type):
+            return [rule.get("message", f"必须使用 {target}")]
+        return []
+
+
+class MustNotExistNodeEngine(BaseEngine):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        node_type = mapping.get(target, target)
+        if self.has_node(tree.root_node, node_type):
+            return [rule.get("message", f"不能使用 {target}")]
+        return []
diff --git a/ast_checker/engines/operator.py b/ast_checker/engines/operator.py
new file mode 100644
index 0000000..2f8937d
--- /dev/null
+++ b/ast_checker/engines/operator.py
@@ -0,0 +1,10 @@
+from .base import BaseEngine
+
+
+class MustUseOperatorEngine(BaseEngine):
+    def check(self, tree, rule, language, mapping):
+        target = rule["target"]
+        mapped_op = mapping.get(target, target)
+        if not self.has_node(tree.root_node, mapped_op):
+            return [rule.get("message", f"必须使用 {target} 运算符")]
+        return []