Hydraulic driving device of air compressor

The utility model provides a hydraulic driving device of an air compressor, which comprises a hydraulic motor, a driving shaft of which is connected with a main shaft of an air compressor, and is characterized in that an oil inlet of the hydraulic motor is connected with an oil inlet pipe, the oil inlet pipe is sequentially provided with a solenoid directional valve, a check valve and a hydraulic pump, wherein the oil inlet end of the oil inlet pipe is connected with an oil tank, an oil outlet of the hydraulic motor is connected with an oil outlet pipe, and after being connected with the same solenoid directional valve on the oil inlet pipe, the oil outlet pipe is connected with the oil tank. The traditional air compressor driven by a motor is changed to be driven by the hydraulic motor, therefore, only a vehicle-mounted 24V direct-current power supply for a special vehicle for railway maintenance machines needs to be used to cause the whole hydraulic motor system to start working, so as to drive an air brake system to brake the special vehicle for the railway maintenance machines, more electric power is not needed any more, not only vehicle-mounted diesel amount is reduced, and the operation load of the whole vehicle is reduced, but also fuel is saved, cost is reduced, and railway maintenance is facilitated.