The core component of the light hybrid vehicle is the hybrid power system. According to the structure characteristics and working process of a light hybrid vehicle, the development program of the testing system has been put forward in this paper. CAN bus and the modular design idea have been adopted in the test system. The system is divided into dynamometer module, motor module, battery module, load simulation module and PC management system, etc. The performance of the key components is tested through two kinds of standard and the pattern of custom. The control of data recording and processing and output test results are completed by the management system.