We design a hydraulic system for a new multi-stage pressure source loader. The principle and research status of this system are introduced. Using the softwares AMESim and MATLAB/Simulink,we build a mathematical model of the hydraulic system for the new loader's steering and working device. A control system of the system is designed and studied. The external load of the loader under typical operating conditions is taken as the input of the system. After the joint simulation,it is found that there are problem...