With comprehensive consideration of the structure, kinematics, thermodynamics problems of the automotive disc brake, a time model of brake disk in Matlab, a structure model and a temperature field model of brake disk in ANSYS were built, and the multidisciplinary optimization analysis and design could be made by numerical analysis and calculation. Integrating iSIGHT with Matlab and ANSYS, the platform and simulation processes of multidisciplinary design optimization (MDO) of the disk brake were constructed. In order to achieve the parameters extraction, export and update as well as the data exchanges between the software, the customized development of the software has been made. The result from the platform test demonstrated that the braking effect was improved, the braking time was shortened and the weight of the brake was reduced.