Abstract: Dynamic control error of precise two-dimensional mirror was the important influencing error factor on simulation precision of the laser guided weapon countermeasure simulation system, the accurate error model was the foundation for precision analysis of the simulation system. At present classical frequency method was adopted to analyze the control error by setting up the transfer function of the servo system, the modeling process was complex and accurate model was not easy to build. Then the paper gave the principle of the identification method, the design approach of input LFM signal, the ranks and parameters of the equivalent control error model which was built by using RWLS method. The proposed model was verified by simulative test by inputting the sine signal according to the performance index of the mirror. The result showed that the estimate output was consistent with the simulation output: the estimate average error and maximum error were 0and 13 respectively, which explained the accuracy of the control error model and provided the support for modeling the dynamical control error of other simulation equipment in the simulation system.