In order to test the electric power steering system(EPS)of motor on bench, a control system of EPS test platform based on Siemens SIMOTION D was designed.On the test platform the performance and parameters of EPS were tested by imitating the turning angle of steering wheel and turning torque of vehicle wheel during the process of motor turning.Relevant test data were provided to developers to optimize and improve the EPS, and the development cycle and cost of the EPS product in real vehicle test were reduced.The hardware system and software system of the test platform were designed.Trial experiments were carried out on the test platform.The result shows that the design plan is reasonable and reliable.The desired good running condition of the system is achieved.