Abstract: Through analyzing the problem of coal mine explosion-proof 4WD vehicle that takes hydraulic transmission as power control, an improved design scheme for power control device is proposed. The design adopts hydraulic control type power cut off device, and power shift gearbox in the configuration of control device can realize power cut between the transmission device and the wheel and can realize the interlock between driving brake and shifting clutch manipulation, which meets automatic power cut-off function in driving brake and parking brake, reduces and eliminates the parasitic power when the vehicle is in the brake. The system has reasonable structure and good university, and can realize the direct transformation of the existing vehicles.