Aiming at the shortcomings of current mechanical excavation such as single function, huge volume, low degree of automation, and taking many operators, a crawler-type sump cleaning robot was designed, and the hydraulic system of its walking unit was simulated and analyzed. The dynamic characteristics under working conditions such as straight running on the flat ground, steering, and climbing were simulated and analyzed.The results show that the walking unit of the sump cleaning robot can complete the specified actions according to the requirements of the working conditions, and it is not affected by the change of external resistance during the driving process. At the same time, each actuator can work independently without interference each other, which reflects a good ability to resist flow saturation. In addition, the energy-saving efficiency of the load-sensing system and the throttling speed-regulating system with constant pump were simulated.The results show that the load-sensing system is more efficient and energy-saving.