Abstract:In view of the problem that the speed setting of executing mechanism of hydraulic excavator needed to replace the multi way valve spool, based on the electro hydraulic proportional technology of hydraulic excavator, a set of speed set system for executing mechanism of hydraulic excavator was designed. The system composition, working principle and the method of the program realization of the speed setting function were described. By the system, drivers were allowed to set the speed of the executing mechanism of hydraulic excavator by the electric control handle according to various requirements, especially the speed of complex motion of the two executing mechanism,without replacing the multiway valve spool. The speed would be recorded by PLC after setting,and it was used to replace the data in excavator controller,to ensure that the executing mechanism of hydraulic excavator would be working according to the set speed.