The invention discloses a feeding hydraulic control system of a mountain modular drilling machine, and belongs to the technical field of mining of mining coal bed gas. The feeding hydraulic control system comprises a main pump set, an auxiliary pump, a feeding system oil cylinder, an oil tank, multi-way reversing valves, a drilling pressure control valve set and the like. The feeding hydraulic control system can adapt to drilling requirements under different working conditions; under the working conditions of normal drilling and hole washing, the feeding system oil cylinder can be used for slow feeding, and the drilling pressure is adjustable; and under the working conditions of reverse drilling, vain drilling rod feeding and power head position adjusting, the feeding system oil cylinder can move ahead and move back rapidly. The concept of energy conservation is taken into consideration to design the feeding hydraulic control system and a differential loop is designed, wherein in the lifting process, upper cavity hydraulic oil is supplied to a lower cavity, so that the oil supply amount to an oil pump is reduced, and energy conservation is achieved; and in the pressure reduction drilling process, a flow feedback type speed control valve block is designed to solve the problem of unstable lowering speed, so that steady-speed drilling is achieved.