diff --git a/internal/entity/models/deepseek.go b/internal/entity/models/deepseek.go
index 4e278f1911..d19f66aaa2 100644
--- a/internal/entity/models/deepseek.go
+++ b/internal/entity/models/deepseek.go
@@ -293,7 +293,11 @@ func (d *DeepSeekModel) ChatStreamlyWithSender(modelName string, messages []Mess
 		if chatModelConfig.Thinking != nil {
 			if *chatModelConfig.Thinking {
 				var thinkingFlag string
-				switch *chatModelConfig.Effort {
+				effort := "high"
+				if chatModelConfig.Effort != nil {
+					effort = *chatModelConfig.Effort
+				}
+				switch effort {
 				case "none":
 					thinkingFlag = "disabled"
 					break
diff --git a/internal/entity/models/volcengine.go b/internal/entity/models/volcengine.go
index 2e3f543f21..b33ec4971e 100644
--- a/internal/entity/models/volcengine.go
+++ b/internal/entity/models/volcengine.go
@@ -257,6 +257,10 @@ func (v *VolcEngine) ChatStreamlyWithSender(modelName string, messages []Message
 		"temperature": 1,
 	}
 
+	if modelConfig == nil {
+		modelConfig = &ChatConfig{}
+	}
+
 	if modelConfig.Stream != nil {
 		reqBody["stream"] = *modelConfig.Stream
 	}
@@ -285,7 +289,11 @@ func (v *VolcEngine) ChatStreamlyWithSender(modelName string, messages []Message
 	if modelConfig.Thinking != nil {
 		if *modelConfig.Thinking {
 			var thinkingFlag string
-			switch *modelConfig.Effort {
+			effort := "medium"
+			if modelConfig.Effort != nil {
+				effort = *modelConfig.Effort
+			}
+			switch effort {
 			case "none", "minimal":
 				thinkingFlag = "disabled"
 				reqBody["reasoning_effort"] = "minimal"