diff --git a/spine-ts/spine-construct3/src/aces.json b/spine-ts/spine-construct3/src/aces.json
index fe91794ac..6e686338e 100644
--- a/spine-ts/spine-construct3/src/aces.json
+++ b/spine-ts/spine-construct3/src/aces.json
@@ -316,6 +316,18 @@
           }
         ]
       },
+      {
+        "id": "set-default-mix",
+        "scriptName": "SetDefaultMix",
+        "highlight": false,
+        "params": [
+          {
+            "id": "duration",
+            "type": "number",
+            "initial-value": 0
+          }
+        ]
+      },
       {
         "id": "set-physics-mode",
         "scriptName": "SetPhysicsMode",
diff --git a/spine-ts/spine-construct3/src/c3runtime/actions.ts b/spine-ts/spine-construct3/src/c3runtime/actions.ts
index 8910215fb..aec182b46 100644
--- a/spine-ts/spine-construct3/src/c3runtime/actions.ts
+++ b/spine-ts/spine-construct3/src/c3runtime/actions.ts
@@ -97,6 +97,10 @@ C3.Plugins.EsotericSoftware_SpineConstruct3.Acts =
 		this.setAnimationMix(fromName, toName, duration);
 	},
 
+	SetDefaultMix (this: SDKInstanceClass, duration: number) {
+		this.setDefaultMix(duration);
+	},
+
 	SetPhysicsMode (this: SDKInstanceClass, mode: 0 | 1 | 2 | 3) {
 		this.setPhysicsMode(mode);
 	},
diff --git a/spine-ts/spine-construct3/src/c3runtime/instance.ts b/spine-ts/spine-construct3/src/c3runtime/instance.ts
index 8ce1f8d68..e796a3db9 100644
--- a/spine-ts/spine-construct3/src/c3runtime/instance.ts
+++ b/spine-ts/spine-construct3/src/c3runtime/instance.ts
@@ -616,6 +616,16 @@ class SpineC3Instance extends globalThis.ISDKWorldInstanceBase {
 		}
 	}
 
+	public setDefaultMix (duration: number) {
+		const stateData = this.state?.data;
+		if (!stateData) {
+			console.warn('[Spine] setDefaultMix: no state data');
+			return;
+		}
+
+		stateData.defaultMix = duration;
+	}
+
 	public setTrackAlpha (alpha: number, trackIndex: number) {
 		const { state } = this;
 		if (!state) {
diff --git a/spine-ts/spine-construct3/src/lang/en-US.json b/spine-ts/spine-construct3/src/lang/en-US.json
index cbb920a58..318383661 100644
--- a/spine-ts/spine-construct3/src/lang/en-US.json
+++ b/spine-ts/spine-construct3/src/lang/en-US.json
@@ -398,6 +398,17 @@
               }
             }
           },
+          "set-default-mix": {
+            "list-name": "Set default mix",
+            "display-text": "Set default mix duration to {0}",
+            "description": "Set the default crossfade duration used when transitioning between animations that don't have a specific mix defined",
+            "params": {
+              "duration": {
+                "name": "Duration",
+                "desc": "Default blend duration in seconds"
+              }
+            }
+          },
           "set-physics-mode": {
             "list-name": "Set physics mode",
             "display-text": "Set physics mode to {0}",
diff --git a/spine-ts/spine-construct3/src/lang/zh-CN.json b/spine-ts/spine-construct3/src/lang/zh-CN.json
index 92953ab31..299d9e49f 100644
--- a/spine-ts/spine-construct3/src/lang/zh-CN.json
+++ b/spine-ts/spine-construct3/src/lang/zh-CN.json
@@ -398,6 +398,17 @@
               }
             }
           },
+          "set-default-mix": {
+            "list-name": "设置默认混合",
+            "display-text": "设置默认混合时长为{0}",
+            "description": "设置动画过渡时使用的默认混合时长（当没有为特定动画对定义混合时长时使用）",
+            "params": {
+              "duration": {
+                "name": "时长",
+                "desc": "默认混合时长（秒）"
+              }
+            }
+          },
           "set-physics-mode": {
             "list-name": "设置物理模式",
             "display-text": "设置物理模式为{0}",