diff --git a/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.cc b/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.cc
index a64f85ee9ac1a7bb8f0ed7bb8678166bbbcd5746..96befe7f8a5d16402338ac337daa96d714b4d310 100644
--- a/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.cc
+++ b/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.cc
@@ -460,77 +460,6 @@ inline bool CheckNodeIndegreeEquals(const Node &node, size_t n) {
   return node.inputs.size() == n;
 }
 
-NodesTSIterator::NodesTSIterator(const std::vector<Node *> &source) {
-  PADDLE_ENFORCE(!source.empty(),
-                 "Start points of topological sorting should not be empty!");
-  // CHECK all the inputs' in-degree is 0
-  for (auto *node : source) {
-    PADDLE_ENFORCE(CheckNodeIndegreeEquals(*node, 0));
-  }
-
-  std::unordered_set<Node *> visited;
-  std::unordered_set<Node *> to_visit{source.begin(), source.end()};
-
-  std::vector<Node *> inlink_visited;
-  while (!to_visit.empty()) {
-    std::vector<Node *> queue(to_visit.begin(), to_visit.end());
-    for (auto *p : queue) {
-      if (Agent(p).deleted()) {
-        visited.insert(p);
-        to_visit.erase(p);
-      }
-
-      inlink_visited.clear();
-
-      std::copy_if(p->inputs.begin(), p->inputs.end(),
-                   std::back_inserter(inlink_visited),
-                   [&](Node *x) -> bool { return visited.count(x) != 0; });
-
-      if (inlink_visited.size() == p->inputs.size()) {
-        sorted_.push_back(p);
-        for (auto *_ : p->outputs) {
-          if (!visited.count(_)) {
-            to_visit.insert(_);
-          }
-        }
-
-        to_visit.erase(p);
-        visited.insert(p);
-      }
-    }
-  }
-}
-
-NodesTSIterator::NodesTSIterator(const NodesTSIterator &other)
-    : sorted_(other.sorted_), cursor_(other.cursor_) {}
-
-Node &NodesTSIterator::operator*() {
-  PADDLE_ENFORCE_LT(cursor_, sorted_.size());
-  return *sorted_[cursor_];
-}
-
-NodesTSIterator &NodesTSIterator::operator++() {
-  if (++cursor_ >= sorted_.size()) {
-    sorted_.clear();
-    cursor_ = 0;
-  }
-  return *this;
-}
-NodesTSIterator &NodesTSIterator::operator=(const NodesTSIterator &other) {
-  cursor_ = other.cursor_;
-  sorted_ = other.sorted_;
-  return *this;
-}
-
-bool NodesTSIterator::operator==(const NodesTSIterator &other) {
-  return sorted_ == other.sorted_ && cursor_ == other.cursor_;
-}
-
-Node *NodesTSIterator::operator->() {
-  PADDLE_ENFORCE_LT(cursor_, sorted_.size());
-  return sorted_[cursor_];
-}
-
 }  // namespace analysis
 }  // namespace inference
 }  // namespace paddle
diff --git a/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.h b/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.h
index ea88edd042aa9d46f66af1aa92f2cb273696c118..5d11c217b69f11d45c6fb6d552dc404fa8313daf 100644
--- a/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.h
+++ b/paddle/fluid/inference/analysis/ir_passes/subgraph_detector.h
@@ -30,6 +30,7 @@ namespace inference {
 namespace analysis {
 
 using framework::ir::Graph;
+using framework::ir::NodesTSIterator;
 
 const char kIsFunctionNode[] = "__is_function_node__";
 const char kFunctionNodeSubGraph[] = "__function_node_sub_graph__";
@@ -132,32 +133,6 @@ struct Agent {
   framework::ir::Node *x_;
 };
 
-// Topological sorting iterator on nodes.
-struct NodesTSIterator
-    : public std::iterator<std::forward_iterator_tag, framework::ir::Node *> {
-  NodesTSIterator() = default;
-  explicit NodesTSIterator(const std::vector<framework::ir::Node *> &source);
-  NodesTSIterator(NodesTSIterator &&other)
-      : sorted_(std::move(other.sorted_)), cursor_(other.cursor_) {
-    other.cursor_ = 0;
-  }
-  NodesTSIterator(const NodesTSIterator &other);
-
-  framework::ir::Node &operator*();
-  NodesTSIterator &operator++();
-  // TODO(Superjomn) current implementation just compare the first
-  // element, need to compare the graph and all the elements in the queue and
-  // set.
-  NodesTSIterator &operator=(const NodesTSIterator &other);
-  bool operator==(const NodesTSIterator &other);
-  bool operator!=(const NodesTSIterator &other) { return !(*this == other); }
-  framework::ir::Node *operator->();
-
- private:
-  std::vector<framework::ir::Node *> sorted_;
-  size_t cursor_{0};
-};
-
 // The nodes those have no input will be treated as start points.
 static std::vector<framework::ir::Node *> ExtractStartPoints(const Graph &g) {
   std::vector<framework::ir::Node *> result;