The invention relates to the technical field of automobile rush-repair, and discloses an auxiliary device for an automobile rush-repair trailer. The auxiliary device includes a machine frame, a firstconveying part and a second conveying part. The first conveying part includes a first supporting block and a base; the first supporting block is provided with supporting plates; the supporting platesare provided with supporting shafts and a pushing shaft; the pushing shaft is internally threadingly connected with a screw; the screw is fixedly connected with a secondary bevel gear; the base is provided with a first motor; and an output shaft of the first motor is fixedly connected with a primary bevel gear. The second conveying part includes a second supporting block and a supporting seat; thesecond supporting block is provided with supporting rods; the lower parts of the supporting rods are provided with air cavities; piston plates are disposed inside the air cavities; the bottoms of thepiston plates are provided with springs; the supporting rods are provided with air bags; the air cavities are provided with one-way valves; outer parts of the first supporting block and the second supporting block are sleeved by a conveyor belt; the conveyor belt is hinged to conveying rollers; and the conveying rollers are hinged to conveying plates, and the two adjacent conveying plates are hinged. The auxiliary device is simple in structure, and a fault automobile can be conveyed through the conveyor belt, and the problem existing in a crane can be solved.