Automobile plays an indispensable role in people's daily life, and the frame, as the main bearing part of the automobile, always affects the performance of the automobile and people's driving safety. The reliability of the truck frame is an important part of the inspection of the automotive quality. Because the frame of light truck is a complex structure, the general reliability analysis methods such as first-order second-moment method and second-order second-moment method cannot accurately solve the reliability index of complex systems, while Monte Carlo simulation has a large amount of computation and low efficiency. Therefore, this paper proposes a technique for the reliability of the truck frame combining response surface methodology and advanced first-order second-moment method. In this method, the response surface methodology is employed to obtain the performance function of the truck frame and advanced first-order second-moment method is used to obtain the reliability of the truck frame. The reliability analysis results of the light truck frame show the feasibility and effectiveness of the proposed method.