diff --git a/taichi/ir/basic_stmt_visitor.cpp b/taichi/ir/basic_stmt_visitor.cpp
index e8d112d3bdc89..a52c019589094 100644
--- a/taichi/ir/basic_stmt_visitor.cpp
+++ b/taichi/ir/basic_stmt_visitor.cpp
@@ -8,12 +8,9 @@ BasicStmtVisitor::BasicStmtVisitor() {
 }
 
 void BasicStmtVisitor::visit(Block *stmt_list) {
-  auto backup_block = current_block;
-  current_block = stmt_list;
   for (auto &stmt : stmt_list->statements) {
     stmt->accept(this);
   }
-  current_block = backup_block;
 }
 
 void BasicStmtVisitor::visit(IfStmt *if_stmt) {
diff --git a/taichi/ir/ir.cpp b/taichi/ir/ir.cpp
index b4613ca630ee6..5f1c4c33daca6 100644
--- a/taichi/ir/ir.cpp
+++ b/taichi/ir/ir.cpp
@@ -565,8 +565,6 @@ IRNode *FrontendContext::root() {
 
 std::unique_ptr<FrontendContext> context;
 
-Block *current_block = nullptr;
-
 Expr Var(const Expr &x) {
   auto var = Expr(std::make_shared<IdExpression>());
   current_ast_builder().insert(std::make_unique<FrontendAllocaStmt>(
diff --git a/taichi/ir/ir.h b/taichi/ir/ir.h
index 80a6964052c16..4036597d83f7e 100644
--- a/taichi/ir/ir.h
+++ b/taichi/ir/ir.h
@@ -1921,10 +1921,6 @@ class RangeAssumptionExpression : public Expression {
   }
 };
 
-// TODO: fix this hack...
-// for current ast
-extern Block *current_block;
-
 class IdExpression : public Expression {
  public:
   Identifier id;
diff --git a/taichi/transforms/lower_access.cpp b/taichi/transforms/lower_access.cpp
index aee109ad8478e..f7230ec4946d8 100644
--- a/taichi/transforms/lower_access.cpp
+++ b/taichi/transforms/lower_access.cpp
@@ -17,12 +17,9 @@ class LowerAccess : public IRVisitor {
   }
 
   void visit(Block *stmt_list) override {
-    auto backup_block = current_block;
-    current_block = stmt_list;
     for (auto &stmt : stmt_list->statements) {
       stmt->accept(this);
     }
-    current_block = backup_block;
   }
 
   void visit(IfStmt *if_stmt) override {
diff --git a/taichi/transforms/statement_replace.cpp b/taichi/transforms/statement_replace.cpp
index 763d6debf93a9..635423276c177 100644
--- a/taichi/transforms/statement_replace.cpp
+++ b/taichi/transforms/statement_replace.cpp
@@ -28,12 +28,9 @@ class StatementReplace : public IRVisitor {
   }
 
   void visit(Block *stmt_list) override {
-    auto backup_block = current_block;
-    current_block = stmt_list;
     for (auto &stmt : stmt_list->statements) {
       stmt->accept(this);
     }
-    current_block = backup_block;
   }
 
   void visit(IfStmt *if_stmt) override {