Based on the requirements of VSV actuator tracking error,the factors that affect the tracking error were analyzed.From the factors,the methods to reduce error were researched.Firstly,from given error and feedback error,the influence degree of accuracy of the tracking error was analyzed.And then,a dynamic model of electrichydraulic position servo system was established based on the principle analysis of VSV actuator.Load was the main factors influencing the tracking error based on analysis from the dynamic model.The method of displacement compensation was put forward,through the load valve and its speed.Finally,some relative performance tests were conducted on half physics test rig.The results indicate that the analysis of tracking error sources is accuracy,and through the simulation test the effectiveness of the displacement compensation method is verified.