Abstract： An attitude fault tolerant control and flexible vibration suppression approach was proposed for the flexible satellite with actuator faults and orbit control force based on the adaptive sliding mode control method. This fault-tolerant control method does not need fault information. The adaptive control algorithm makes it estimate uncertain parameters effectively and thereby the stability and robustness of the attitude system are guaranteed in the presence of external and internal disturbance and inertia moment uncertainty. Based on this, an nonlinear state observer was designed for nonlinear term and disturbance by using the accurate robust differentiator theory, and the flexible chattering was accordingly depressed by combining adaptive control with sliding mode control methods. Finally, a simulation was conducted in actuator failure cases on the premise of reaction flywheel redundancy configuration during orbit control process. The simulation results demonstrate the validity and correctness of the designed control approaches.