Abstract: Reaction wheel is one of the main disturbance sources that affect the precision of attitude control system of spacecraft. The purpose of setting up a disturbance model of reaction wheel is to predict the effects of the disturbance on the spacecraft, and then adopt corresponding control methods and isolation systems to restrain them. This paper presents the experimental disturbance model of reaction wheel. By analyzing the experimental data of reaction wheel, the parameters of the disturbance model, harmonic numbers and amplitude coefficients are determined. The energy compensation method is then given. The simulation results show that the identification accuracy of harmonic numbers does not exceed 0.04%. When adopting the amplitude spectrum method to compute the amplitude coefficients, the error is high up to 15.5%, however the error not over 1.1% when adopting energy compensation method. It indicates that the energy compensation method improves the identification accuracy of amplitude coefficients. This paper aims at providing a certain basis for improving the attitude control precision and stabilization of the spacecraft.