Self-help travel driving device of truck semi-trailer

The invention discloses a self-help travel driving device of a truck semi-trailer. The self-help travel driving device comprises a pneumatic control system, a hydraulic drive system and a trailer drive shaft assembly, wherein the pneumatic control system is arranged on a main vehicle, the hydraulic drive system is arranged on the main vehicle and the trailer, the pneumatic control system comprises a force taking switch, a solenoid valve, a gas circuit pipeline and a working cylinder, the force taking switch is connected with the solenoid valve, the output end of the hydraulic drive system is connected with the trailer drive shaft assembly, the trailer drive shaft assembly comprises a trailer drive shaft axle shell, a trailer speed reducer, a semi shaft, a trailer wheel hub and a flange plate shaft head lock, the output end of the hydraulic drive system is connected with the input end of the trailer speed reducer, and the flange plate shaft head lock is arranged on the trailer wheel hub. The self-help travel d