diff --git a/consensus/posv/posv.go b/consensus/posv/posv.go
index d571ffe554..40e1381845 100644
--- a/consensus/posv/posv.go
+++ b/consensus/posv/posv.go
@@ -211,7 +211,8 @@ type Posv struct {
 	signFn clique.SignerFn // Signer function to authorize hashes with
 	lock   sync.RWMutex    // Protects the signer fields
 
-	HookReward func(chain consensus.ChainReader, state *state.StateDB, header *types.Header) error
+	HookReward  func(chain consensus.ChainReader, state *state.StateDB, header *types.Header) error
+	HookPrepare func(header *types.Header, signers []common.Address) error
 }
 
 // New creates a Posv proof-of-stake-voting consensus engine with the initial
@@ -654,6 +655,12 @@ func (c *Posv) Prepare(chain consensus.ChainReader, header *types.Header) error
 	if header.Time.Int64() < time.Now().Unix() {
 		header.Time = big.NewInt(time.Now().Unix())
 	}
+
+	if c.HookPrepare != nil {
+		signers := snap.signers()
+		c.HookPrepare(header, signers)
+	}
+
 	return nil
 }
 
diff --git a/eth/backend.go b/eth/backend.go
index 191d9aeaad..9499b7dea8 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -209,6 +209,42 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		}
 		eth.protocolManager.fetcher.SetImportedHook(importedHook)
 
+		// Hook will process when preparing block.
+		c.HookPrepare = func(header *types.Header, signers []common.Address) error {
+			client, err := eth.blockchain.GetClient()
+			if err != nil {
+				log.Error("Fail to connect IPC client for penalty.", "error", err)
+			}
+			number := header.Number.Int64()
+			// Check m2 exists on chaindb.
+			// Get secrets and opening at epoc block checkpoint.
+			if number > 0 && number%common.EpocBlockRandomize == 0 {
+				var candidates []int64
+				lenSigners := int64(len(signers))
+
+				if lenSigners > 0 {
+					for _, addr := range signers {
+						random, err := contracts.GetRandomizeFromContract(client, addr)
+						if err != nil {
+							log.Error("Fail to get random m2 from contract.", "error", err)
+						}
+						candidates = append(candidates, random)
+					}
+
+					// Get randomize m2 list.
+					m2, err := contracts.GenM2FromRandomize(candidates, lenSigners)
+					if err != nil {
+						log.Error("Can not get m2 from randomize SC", "error", err)
+					}
+					if len(m2) > 0 {
+						header.Validators = contracts.BuildValidatorFromM2(m2)
+					}
+				}
+			}
+
+			return nil
+		}
+
 		// Hook reward for posv validator.
 		c.HookReward = func(chain consensus.ChainReader, state *state.StateDB, header *types.Header) error {
 			client, err := eth.blockchain.GetClient()
@@ -252,39 +288,6 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 				}
 			}
 
-			// Check m2 exists on chaindb.
-			// Get secrets and opening at epoc block checkpoint.
-			if number > 0 && number%common.EpocBlockRandomize == 0 {
-				var candidates []int64
-				// Get signers from snapshot.
-				snap, err := c.GetSnapshot(eth.blockchain, chain.CurrentHeader())
-				if err != nil {
-					log.Error("Fail to get snapshot for get secret and opening.", "error", err)
-					return err
-				}
-				signers := snap.Signers
-				lenSigners := int64(len(signers))
-
-				if lenSigners > 0 {
-					for addr := range signers {
-						random, err := contracts.GetRandomizeFromContract(client, addr)
-						if err != nil {
-							log.Error("Fail to get random m2 from contract.", "error", err)
-						}
-						candidates = append(candidates, random)
-					}
-
-					// Get randomize m2 list.
-					m2, err := contracts.GenM2FromRandomize(candidates, lenSigners)
-					if err != nil {
-						log.Error("Can not get m2 from randomize SC", "error", err)
-					}
-					if len(m2) > 0 {
-						header.Validators = contracts.BuildValidatorFromM2(m2)
-					}
-				}
-			}
-
 			return nil
 		}
 	}