This paper discusses developing the iOS multimedia messaging module in Easytalk mobile system.Analyzes and researches some often used design patterns and the realized with unique advantages in iOS platform.In the entire development process of iOS multimedia messaging system this paper records reasonable solution which solves specific problems by importing the idea of design patterns.From the oriented interface programming importing the idea of design patterns will reduce the code coupling and increase the code scalability and robustness.This paper also takes a global view of realized the multimedia messaging system.This system has passed the test at present and Easytalk can be downloaded in Appstore also.