This paper presents a fault-tolerant formation control (FTFC) for fixed-wing UAVs suffering from actuator bias faults under the differential game and the fully actuated system (FAS) framework. The failed fixed-wing UAV model is transformed into the FAS, helping to eliminate the system’s nonlinearity and compensate for the faults. Adaptive fault observers are established for estimating the actuator faults, based on which, the fault-tolerant formation controllers are designed by combining the differential game and the FAS approach. It is rigorously justified that the fault estimation errors and the formation errors are asymptotically stable, and the open-loop Nash equilibrium is achieved by solving the coupled Riccati differential equations (CRDEs). Moreover, a fault-tolerant control receding horizon control (FTC-RHC) algorithm is proposed to solve the CRDEs, such that a real-time game controller for FTFC can be obtained. Finally, an example of fixed-wing UAVs is provided to prove the validity of the method proposed.