var filename = Server.MapPath(@"data/a.exe"); Assembly asm = System.Reflection.Assembly.LoadFile(filename); Type type = asm.GetType("aaaa"); Object oper = Activator.CreateInstance(type); object[] paras = new object[] { 'a','b'}; MethodInfo method = t.GetMethod("CreateSMS"); BindingFlags flag = BindingFlags.Public | BindingFlags.Instance; object result = method.Invoke(oper, flag, Type.DefaultBinder, paras, null);