The Organic Rankine Cycle System (ORC) is an effective means to use the solar energy. The system adopts the solar energy on the car roof as the heat source to make the ORC work and drive the thermoelectric air-conditioner. It can improve the entering comfort on the parking condition and the vehicle energy utilization efficiency. In this research, the system comprehensively applied the principle of sunshine concentration, heat collection and photo electricity. Then considering the working condition and performance features of ORC system, the car roof was designed to have a compact structure, through which the efficiency of the solar vehicle system could be improved. Firstly, the research analyzed the heat source temperature and the heat flux impact on the output power of the ORC system. After that, the performance of heat collection was identified according to the given thermoelectric air-condition’s power requirements. After building the model of three kinds of solar collectors, through the analysis and frequency division utilization of it, the basic requirements about stable output power by the solar energy could meet on the condition of different illumination. By the research and analysis, the ORC system could run normally and the output power was changed by sunlight’s condition with a certain scope of illuminance and a certain incident angle. Besides, the use of roof’s solar power could supply energy for a part of vehicle’s electric system and reduce energy consumption.