Hydraulic system for development machine

The utility model provides a hydraulic system used for a development machine, belonging to an open hydraulic system. The hydraulic system used for the development machine is characterized in that a constant power load sensitive axial plunger piston variable pump capable of cutting the pressure is connected with a six-way ratio multichannel reversing valve capable of compensating the pressure and sensing the load by a pipeline, the six-way ratio multichannel reversing valve is provided with plate valves which are respectively connected with and controls each executing mechanism, a pressure compensating valve is respectively connected with each plate valve oil inlet pipeline for adjusting a flow value of each plate valve, and a leading control opening of the ratio multichannel valve is connected with a manual ratio leading valve. The whole system has the function of power adaption, increases the ratio of power to weight of the hydraulic system, and solves the problems of the hydraulic system formed by a wheel pump and a manual multichannel valve that the leakage is serious, the power loss is great, the pressure is low, the oil fluid temperature is high and the reliability is low; and a ratio leading handle ensures that a driver can operate more comfortably and safely, and the action is more accurate and the reliability is improved greatly.