Autonomous driving test method is an important part of autonomous driving research systems, and it is also one of the current research hotspots. In this paper, an automatic driving test method based on risk scenario search is proposed. The swap scenario is extracted through the NGSIM (Next Generation Simulation) dataset, and the scope and characteristics of the scene parameter space are determined. To improve the efficiency of scene generation, the search process of scene parameters is enhanced, constraining the lanechanging scene of the preceding vehicle, optimizing the simulation time of a single scene, and adding a memory module to prevent the same scene from repeated testing. A three-lane leading vehicle lane-changing scenario is constructed based on the PreScan/Simulink platform, and 439 scenarios are generated and tested, among which 266 scenarios result in vehicle collisions. It is found that collision failures are caused by the delayed action of the measuring system and the failure to trigger emergency braking.