At present, the hydraulic systems of sanitation vehicles are based on quantified pump hydraulic systems containing ordinary electromagnetic valves in domestic market. However, a wide range of issues exist in these systems, such as high heat, great assistant engine’s power loss, possible blockage of speed regulating damper, unstable operation. This paper studies the application of substituting proportional control hydraulic system for quantified pump hydraulic system. The proportional control of output flow is realizable through using proportional electrical signal as input. The proportional control hydraulic system has a lot of advantages, such as automatic pressure compensation, stepless speed regulation, program control, undamped throttling, stable operation, relatively environment needs. The energy consumption of the new hydraulic system is only half of the original one. Compared with the old system, the new hydraulic system has made a qualitative leap in energy saving, reliability, intelligent and so on. So the new hydraulic system, proportional control hydraulic system, is the direction for future development of environmental sanitation vehicle hydraulic system.