diff --git a/src/ios/Events.m b/src/ios/Events.m
index 8eac1bd..59fb608 100644
--- a/src/ios/Events.m
+++ b/src/ios/Events.m
@@ -13,7 +13,7 @@
 @implementation Events
 
 static NSString* PREFIX = @"com.tencent.trtc.event";
-static NSDictionary<NSString*,NSMutableOrderedSet<Listener*>*> *events = nil;
+static NSMutableDictionary<NSString*,NSMutableOrderedSet<Listener*>*> *events = nil;
 
 + (void)fireEvent: (NSString*)event{
     [Events fireEvent: nil];
@@ -48,13 +48,17 @@ static NSDictionary<NSString*,NSMutableOrderedSet<Listener*>*> *events = nil;
 
 + (void)init{
     if( events == nil){
-        NSMutableOrderedSet* listeners  = [[NSMutableOrderedSet alloc] init];
-        events = [[NSDictionary alloc] initWithObjectsAndKeys:listeners,@"com.tencent.trtc.eventuserinfo.update", nil];
+        events = [NSMutableDictionary dictionary];
     }
 }
 + (NSMutableOrderedSet*) getEventListener: (NSString*)event{
     [Events init];
     NSString* key = [[NSString alloc] initWithFormat:@"%@%@", PREFIX, event ];
+    NSMutableOrderedSet* listeners =[events valueForKey:key];
+    if(listeners == nil){
+        listeners = [[NSMutableOrderedSet alloc] init];
+        [events setObject:listeners forKey:key];
+    }
     return [events valueForKey:key];
 }
 @end