Hydraulic system for tunneling machine

The invention relates to a development machine hydraulic system, belonging to an open type hydraulic system. The invention is characterized in that: a constant power loading sensitive axial plunger variable displacement pump provided with pressure cut-off function is connected with a six-way proportional multichannel conversion valve with functions of pressure compensation and load sensing through a pipe; various plate valves are arranged inside the six-way proportional mutlichannel conversion valve and respectively connected with and control various actuators; pressure compensation valves are respectively connected on oil inlet pipes of various plate valves and used for adjusting flow values of various plate valves; a pilot opening of the proportional multichannel valve is connected with a manual proportional pilot valve. The whole system has the function of power adaptation and solves the problems of gross leak, large power loss, low pressure, high temperature rise of oils and low reliability of a hydraulic system consisting of a gear pump and a manual multiple-way valve. The invention has the advantages of improvement of power/weight ratio of the hydraulic system, more comfortable and safer operation of drivers due to a proportional pilot handle, more precise action and great improvement of reliability.