Power frequency withstand test is the most effective and direct method to identify the insulation of electrical equipment. In order to simplify the assembly process of power frequency withstand test, the infrared technology is applied to the mobile power frequency withstand voltage measurement platform. The transformer fixed position, the measurement platform using the two infrared sensors which installed in the front end of the electric vehicle frame for localization. According to the angle of the stepping motor, the relative position of the electric vehicle frame and the experimental transformer can be calculated by the triangle method, and then the measurement platform is planned. The measuring platform can be realized with the automatic quick docking of the experimental transformer along the path. This technology has been successfully applied.