The invention discloses an auxiliary fixture for automobile part detection. The auxiliary fixture comprises a stepping motor and two fixed plates, wherein the two fixed plates are fixedly connected with the driving end of the stepping motor, a preset included angle is formed between the two fixed plates, clamping plates are rotatably connected to the two fixed plates by virtue of rotating shafts,vertical chutes are respectively formed in the clamping plates, sliding rods are respectively connected to the interiors of the chutes in a sliding mode, connecting rods respectively sleeve the sliding rods in the sliding mode, buffer springs are fixedly connected to the side walls of one side, which is far from the stepping motor, of the two fixed plates, and a connecting plate is fixedly connected to one end, which is far from the fixed plates, of the two buffer springs. According to the auxiliary fixture, the connecting rods are driven to move through the rotation of a servo motor so as todrive the clamping plates and the clamping rods to rotate, the auxiliary fixture is suitable for clamping parts of different sizes, and the clamped parts are driven to overturn through the rotation ofthe stepping motor, so that the parts are conveniently detected all around, and the detection is convenient.