Vehicle E/E system has made a important role in the reliability of whole vehicle with the development of vehicle’s electronic technology development. The testing of E/E system is traditional done after the whole system is finished, so the system problems can not be discovered earlier and it will affect the system’s reliability. This paper has analyzed the vehicle testing method through two aspects including the project’s beginning and ending to improve the vehicle’s reliability. The RCP and HIL testing will be done at the beginning of the project and the function, performance as well as interface testing will be done at the end of the project. This testing method will realize the improvement of the E/E system reliability and economical efficiency.