Aiming at the phenomenon that the excavator electro-hydraulic proportional control system is affected by the nonlinear friction of the hydraulic cylinder,the system stability and control accuracy are reduced,a strategy using a combination of an improved particle swarm algorithm and feedforward compensation was proposed and the control system was optimized to improve the displacement tracking accuracy.The electro-hydraulic system model was established,and the nonlinear friction was described by the improved Stribeck model.The model parameters were identified and optimized by the improved particle swarm algorithm,and a dynamic friction feedforward compensation method was designed according to the principle of structural invariance.On this basis,the experimental research of sinusoidal signal,high-speed working condition and low-speed working condition was carried out.Experimental results show that the proposed Stribeck model and friction compensation control method can effectively improve the phenomenon of low-speed crawling and peaking,and improve the trajectory tracking accuracy by about 45%.