diff --git a/tools/pd-api-bench/cases/controller.go b/tools/pd-api-bench/cases/controller.go
index 00d9261cba8..d6679cad1d9 100644
--- a/tools/pd-api-bench/cases/controller.go
+++ b/tools/pd-api-bench/cases/controller.go
@@ -214,7 +214,7 @@ func (c *httpController) run() {
 	qps := c.GetQPS()
 	burst := c.GetBurst()
 	cliNum := int64(len(c.clients))
-	tt := time.Duration(base/qps*burst*cliNum) * time.Microsecond
+	tt := time.Duration(base*burst*cliNum/qps) * time.Microsecond
 	log.Info("begin to run http case", zap.String("case", c.Name()), zap.Int64("qps", qps), zap.Int64("burst", burst), zap.Duration("interval", tt))
 	for _, hCli := range c.clients {
 		c.wg.Add(1)
@@ -283,7 +283,7 @@ func (c *gRPCController) run() {
 	qps := c.GetQPS()
 	burst := c.GetBurst()
 	cliNum := int64(len(c.clients))
-	tt := time.Duration(base/qps*burst*cliNum) * time.Microsecond
+	tt := time.Duration(base*burst*cliNum/qps) * time.Microsecond
 	log.Info("begin to run gRPC case", zap.String("case", c.Name()), zap.Int64("qps", qps), zap.Int64("burst", burst), zap.Duration("interval", tt))
 	for _, cli := range c.clients {
 		c.wg.Add(1)
@@ -352,7 +352,7 @@ func (c *etcdController) run() {
 	qps := c.GetQPS()
 	burst := c.GetBurst()
 	cliNum := int64(len(c.clients))
-	tt := time.Duration(base/qps*burst*cliNum) * time.Microsecond
+	tt := time.Duration(base*burst*cliNum/qps) * time.Microsecond
 	log.Info("begin to run etcd case", zap.String("case", c.Name()), zap.Int64("qps", qps), zap.Int64("burst", burst), zap.Duration("interval", tt))
 	err := c.Init(c.ctx, c.clients[0])
 	if err != nil {