diff --git a/Sanchime.Functional/Extensions/IEnumerable.cs b/Sanchime.Functional/Extensions/IEnumerable.cs
index ef5e4b7..f60e8a8 100644
--- a/Sanchime.Functional/Extensions/IEnumerable.cs
+++ b/Sanchime.Functional/Extensions/IEnumerable.cs
@@ -93,11 +93,20 @@ public static class IEnumerableExtension
     public static IEnumerable<Unit> ForEach<T>(this IEnumerable<T> source, Action<T> action)
         => source.Map(action.ToFunc()).ToImmutableList();
 
-    public static IEnumerable<R> Bind<T, R>(this IEnumerable<T> source, Func<T, IEnumerable<R>> func)
-        => source.SelectMany(func);
+    public static IEnumerable<R> Bind<T, R>(this IEnumerable<T> source, Func<T, IEnumerable<R>> binding)
+        => source.SelectMany(binding);
 
-    public static IEnumerable<R> Bind<T, R>(this IEnumerable<T> source, Func<T, Option<R>> func)
-        => source.Bind(t => func(t).AsEnumerable());
+    public static IEnumerable<R> Bind<T, R>(this IEnumerable<T> source, Func<T, Option<R>> binding)
+        => source.Bind(val => binding(val).AsEnumerable());
+
+    /// <summary>
+    /// 将二级序列平展
+    /// </summary>
+    /// <param name="source"></param>
+    /// <typeparam name="T"></typeparam>
+    /// <returns></returns>
+    public static IEnumerable<T> Flatten<T>(this IEnumerable<IEnumerable<T>> source)
+        => source.SelectMany(x => x);
 
 
     private static IEnumerable<T> List<T>(T t)