diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4bcbb0b10a..a87e4bec63 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -29,6 +29,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - \#322 - Add option to enable / disable prometheus
 - \#358 - Add more information in build.sh and install.md
 - \#255 - Add ivfsq8 test report detailed version
+- \#404 - Add virtual method Init() in Pass abstract class
 
 ## Task
 
diff --git a/core/src/scheduler/SchedInst.cpp b/core/src/scheduler/SchedInst.cpp
index 61e0c09759..9bd4df944f 100644
--- a/core/src/scheduler/SchedInst.cpp
+++ b/core/src/scheduler/SchedInst.cpp
@@ -84,6 +84,7 @@ load_simple_config() {
 void
 StartSchedulerService() {
     load_simple_config();
+    OptimizerInst::GetInstance()->Init();
     ResMgrInst::GetInstance()->Start();
     SchedInst::GetInstance()->Start();
     JobMgrInst::GetInstance()->Start();
diff --git a/core/src/scheduler/optimizer/HybridPass.cpp b/core/src/scheduler/optimizer/HybridPass.cpp
index d63fc2e819..8bf0d8990d 100644
--- a/core/src/scheduler/optimizer/HybridPass.cpp
+++ b/core/src/scheduler/optimizer/HybridPass.cpp
@@ -23,6 +23,10 @@
 namespace milvus {
 namespace scheduler {
 
+void
+HybridPass::Init() {
+}
+
 bool
 HybridPass::Run(const TaskPtr& task) {
     // TODO: future, Index::IVFSQ8H, if nq < threshold set cpu, else set gpu
diff --git a/core/src/scheduler/optimizer/HybridPass.h b/core/src/scheduler/optimizer/HybridPass.h
index 0d02a8bda9..f84a0884f2 100644
--- a/core/src/scheduler/optimizer/HybridPass.h
+++ b/core/src/scheduler/optimizer/HybridPass.h
@@ -37,6 +37,9 @@ class HybridPass : public Pass {
     HybridPass() = default;
 
  public:
+    void
+    Init() override;
+
     bool
     Run(const TaskPtr& task) override;
 };
diff --git a/core/src/scheduler/optimizer/LargeSQ8HPass.cpp b/core/src/scheduler/optimizer/LargeSQ8HPass.cpp
index b9784e3c0a..89bd85ec1f 100644
--- a/core/src/scheduler/optimizer/LargeSQ8HPass.cpp
+++ b/core/src/scheduler/optimizer/LargeSQ8HPass.cpp
@@ -27,7 +27,8 @@
 namespace milvus {
 namespace scheduler {
 
-LargeSQ8HPass::LargeSQ8HPass() {
+void
+LargeSQ8HPass::Init() {
     server::Config& config = server::Config::GetInstance();
     Status s = config.GetEngineConfigGpuSearchThreshold(threshold_);
     if (!s.ok()) {
diff --git a/core/src/scheduler/optimizer/LargeSQ8HPass.h b/core/src/scheduler/optimizer/LargeSQ8HPass.h
index 9d135d413a..1afd240c0f 100644
--- a/core/src/scheduler/optimizer/LargeSQ8HPass.h
+++ b/core/src/scheduler/optimizer/LargeSQ8HPass.h
@@ -35,9 +35,12 @@ namespace scheduler {
 
 class LargeSQ8HPass : public Pass {
  public:
-    LargeSQ8HPass();
+    LargeSQ8HPass() = default;
 
  public:
+    void
+    Init() override;
+
     bool
     Run(const TaskPtr& task) override;
 
diff --git a/core/src/scheduler/optimizer/OnlyCPUPass.cpp b/core/src/scheduler/optimizer/OnlyCPUPass.cpp
index 238a91a82c..392ae7940b 100644
--- a/core/src/scheduler/optimizer/OnlyCPUPass.cpp
+++ b/core/src/scheduler/optimizer/OnlyCPUPass.cpp
@@ -24,6 +24,10 @@
 namespace milvus {
 namespace scheduler {
 
+void
+OnlyCPUPass::Init() {
+}
+
 bool
 OnlyCPUPass::Run(const TaskPtr& task) {
     if (task->Type() != TaskType::SearchTask)
diff --git a/core/src/scheduler/optimizer/OnlyCPUPass.h b/core/src/scheduler/optimizer/OnlyCPUPass.h
index 76b42e3766..253775f77e 100644
--- a/core/src/scheduler/optimizer/OnlyCPUPass.h
+++ b/core/src/scheduler/optimizer/OnlyCPUPass.h
@@ -37,6 +37,9 @@ class OnlyCPUPass : public Pass {
     OnlyCPUPass() = default;
 
  public:
+    void
+    Init() override;
+
     bool
     Run(const TaskPtr& task) override;
 };
diff --git a/core/src/scheduler/optimizer/OnlyGPUPass.cpp b/core/src/scheduler/optimizer/OnlyGPUPass.cpp
index 2a72f9757e..69a8366bb2 100644
--- a/core/src/scheduler/optimizer/OnlyGPUPass.cpp
+++ b/core/src/scheduler/optimizer/OnlyGPUPass.cpp
@@ -27,6 +27,10 @@ namespace scheduler {
 OnlyGPUPass::OnlyGPUPass(bool has_cpu) : has_cpu_(has_cpu) {
 }
 
+void
+OnlyGPUPass::Init() {
+}
+
 bool
 OnlyGPUPass::Run(const TaskPtr& task) {
     if (task->Type() != TaskType::SearchTask || has_cpu_)
diff --git a/core/src/scheduler/optimizer/OnlyGPUPass.h b/core/src/scheduler/optimizer/OnlyGPUPass.h
index 10d909d30e..c7a83fea30 100644
--- a/core/src/scheduler/optimizer/OnlyGPUPass.h
+++ b/core/src/scheduler/optimizer/OnlyGPUPass.h
@@ -37,6 +37,9 @@ class OnlyGPUPass : public Pass {
     explicit OnlyGPUPass(bool has_cpu);
 
  public:
+    void
+    Init() override;
+
     bool
     Run(const TaskPtr& task) override;
 
diff --git a/core/src/scheduler/optimizer/Optimizer.cpp b/core/src/scheduler/optimizer/Optimizer.cpp
index 46f24ea712..c5fa311a27 100644
--- a/core/src/scheduler/optimizer/Optimizer.cpp
+++ b/core/src/scheduler/optimizer/Optimizer.cpp
@@ -20,12 +20,12 @@
 namespace milvus {
 namespace scheduler {
 
-// void
-// Optimizer::Init() {
-//    for (auto& pass : pass_list_) {
-//        pass->Init();
-//    }
-// }
+void
+Optimizer::Init() {
+    for (auto& pass : pass_list_) {
+        pass->Init();
+    }
+}
 
 bool
 Optimizer::Run(const TaskPtr& task) {
diff --git a/core/src/scheduler/optimizer/Optimizer.h b/core/src/scheduler/optimizer/Optimizer.h
index bfabbf7de3..68b519e115 100644
--- a/core/src/scheduler/optimizer/Optimizer.h
+++ b/core/src/scheduler/optimizer/Optimizer.h
@@ -38,8 +38,8 @@ class Optimizer {
     explicit Optimizer(std::vector<PassPtr> pass_list) : pass_list_(std::move(pass_list)) {
     }
 
-    //    void
-    //    Init();
+    void
+    Init();
 
     bool
     Run(const TaskPtr& task);
diff --git a/core/src/scheduler/optimizer/Pass.h b/core/src/scheduler/optimizer/Pass.h
index 016b05e457..36a36a1df5 100644
--- a/core/src/scheduler/optimizer/Pass.h
+++ b/core/src/scheduler/optimizer/Pass.h
@@ -34,9 +34,8 @@ namespace scheduler {
 
 class Pass {
  public:
-    //    virtual void
-    //    Init() {
-    //    }
+    virtual void
+    Init() = 0;
 
     virtual bool
     Run(const TaskPtr& task) = 0;