Excavator hydraulic transmission is closely linked, and its development is mainly based on the application of hydraulic technology. Its structure is mainly composed of engine, hydraulic system, working device, traveling device and electrical control. Due to the harsh working conditions of the excavator, the required actions are very complicated, so it puts forward high requirements for the design of the hydraulic system. , its hydraulic system is also the most complex in the hydraulic system of construction machinery. Therefore, the analysis and design of the hydraulic system of the excavator has become an important part of promoting the excavator. Single bucket hydraulic excavator is a kind of mechanical equipment for periodic operation, which consists of three parts: working device, rotary device and traveling device. The working device includes movable, stick and various replacement equipment that can be replaced according to the work needs, such as front shovel, backhoe, loading bucket and grab bucket, etc. The typical working cycle is as follows: