The utility model provides a torque control system for an automobile assembly production line. The torque control system comprises a torque controller and an impact wrench with a torque sensor. The torque controller is connected to the impact wrench by a cable; the impact wrench is connected with an air pipe passing through a solenoid valve; and a control terminal of the solenoid valve is connected with the torque controller. An external terminal of the torque controller is connected with a PLC field module by a signal line and is connected to a production line control system PLC by an industrial network; and the torque controller is also connected with an upper computer by an ethernet local area network. The torque control system has the following advantages: on the basis of effective interlocking of the torque control system detection device and the line body, the worker can screw each bolt according to a regulated sequence and different torsional moments of all bolts based on the process requirement can be realized; and when the worker does not complete process-requirement-based screwing of all bolts at the station within the set time, alarming is carried out timely by the line body and the line body conveying stopping can be realized. Therefore, all work required by the process can be completed.