VACA is a hybrid algorithm combined with the variable metric algorithm and ant colony optimization algorithm. For the electro hydraulic proportional control system for PID parameter tuning problem, this paper puts forward the optimization of PID parameters based on VACA, and gives the specific implementation steps: establish mathematical model for electro-hydraulic control system, establish the simulation model of electro-hydraulic proportional control system of VACA-PID by using SIMULINK toolbox, simulation and verification. The results show that: the VACA-PID controller has good static and dynamic performance, can fully meet the electro-hydraulic proportional control system.