This paper describes an Interactive Platform of Ship Steer System Design based on Matlab. The platform is consist of five function modules: i) modeling module, ii) config module, iii) controller design module, iv) graphic display module, v) data management module. All of the five modules are connected by a main unit which is the center of star network of the platform. It is useful for decreasing the coupling of five sub-modules and exchanging data with each other, and also makes the platform more extensible. The interactive platform is showed to be an efficient tool for enhancing the design process of ship steer system. Finally, a typical example is given to illustrate the utility of the platform.