Without affecting normal operation of traffic, automobile potential energy could be converted to power. A qualitative analysis method was used to research conversion of automobile gravitational potential energy.A system was designed in which an “unnatural” resourcethe gravitational potential energy of automobiles was utilized to generate electricity. The powergeneration system was mainly composed of the hydraulic circuit, the slidercrank mechanism and the power-generation device. With energy recovery method, the traditional power generation device was transformed to a hydraulic and mechanical energy conversion system,to recycle energy on the road. Generating electricity by using potential energy will solve the key problems such as areas, season, distance, pollution etc, which has important significance to research green power.