The accuracy of servo system model affects the analysis and design of controllers directly. The non-linear friction has adverse effects on the high-precision servo system, and the control-oriented system identification is an vitual way to the system analysis recognization.The correlation analysis method can reduce noise strongly, and identify system’s discrete difference model directly. Therefore, it is still widely used. This paper analyzes the effect of Stribeck friction on the servo system at low speed ,and identifys the system by correlation analysis method with a compensated excitation. Then the excitation parameters are analyzed and derived, and the concrete steps is listed. The experimental results show that the method can improve the accuracy of servo system identification with nonlinear frictions.