The attitude tracking control problem of flexible satellites is studied,and a friction compensation sliding mode control algorithm for RBF network is designed.Firstly,the attitude model of flexible satellite attitude is derived based on the imaging mode of the flexible satellite attitude control system.Secondly, according to the tracking error motion model described by the error quaternion,the classical sliding mode control is introduced as the main control framework.Considering the suppression of the observed interference,an Extended State Observer (ESO) is added to observe the total disturbance of the system.Finally,the RBF network friction compensation system is used to approximately estimate the online switching term,and the smoothing of the switching gain in the sliding mode control law is realized,thus to reduce the system vibration.The convergence of the method is proved and deduced theoretically,and simulation is conducted for comparing it with the traditional adaptive method of RBF network approximation,which verifies the theoretical results.