diff --git a/packages/core/src/agent/presets/build.ts b/packages/core/src/agent/presets/build.ts
index 8cb5c69..7c4d653 100644
--- a/packages/core/src/agent/presets/build.ts
+++ b/packages/core/src/agent/presets/build.ts
@@ -21,5 +21,4 @@ export const buildAgent: Omit<AgentInfo, 'name'> = {
 - 使用 git 进行版本控制
 
 始终保持专注和高效，直接解决问题。`,
-  maxSteps: 30,
 };
diff --git a/packages/core/src/agent/presets/explore.ts b/packages/core/src/agent/presets/explore.ts
index ad8f8e4..7822c7f 100644
--- a/packages/core/src/agent/presets/explore.ts
+++ b/packages/core/src/agent/presets/explore.ts
@@ -169,5 +169,4 @@ export const exploreAgent: Omit<AgentInfo, 'name'> = {
       dangerous: 'deny',
     },
   },
-  maxSteps: 20,
 };
diff --git a/packages/core/src/agent/presets/general.ts b/packages/core/src/agent/presets/general.ts
index f39ae6d..290a61b 100644
--- a/packages/core/src/agent/presets/general.ts
+++ b/packages/core/src/agent/presets/general.ts
@@ -45,5 +45,4 @@ export const generalAgent: Omit<AgentInfo, 'name'> = {
     ],
     noTask: true, // 禁止嵌套调用 Task
   },
-  maxSteps: 20,
 };
diff --git a/packages/core/src/agent/presets/plan.ts b/packages/core/src/agent/presets/plan.ts
index 43cc484..4bc857c 100644
--- a/packages/core/src/agent/presets/plan.ts
+++ b/packages/core/src/agent/presets/plan.ts
@@ -189,5 +189,4 @@ export const planAgent: Omit<AgentInfo, 'name'> = {
   model: {
     temperature: 0.5,
   },
-  maxSteps: 30, // 增加探索步数以支持更深入的调研
 };
diff --git a/packages/server/src/agent/adapter.ts b/packages/server/src/agent/adapter.ts
index 7abbbd4..a872569 100644
--- a/packages/server/src/agent/adapter.ts
+++ b/packages/server/src/agent/adapter.ts
@@ -274,6 +274,11 @@ export async function getOrCreateAgent(sessionId: string): Promise<AgentInstance
     const agent = new coreModule.Agent(config);
     agent.setRegistry(coreModule.toolRegistry);
 
+    // 默认使用 Build 模式
+    if (agent.setAgentMode) {
+      agent.setAgentMode('build');
+    }
+
     // 设置权限回调，通过 WebSocket 请求用户确认
     const permissionManager = coreModule.getPermissionManager();
     permissionManager.setAskCallback(createServerPermissionCallback(sessionId));