Using a feedback control law,a sufficient robust fault-tolerant condition is derived based on the solution of Riccati equation. The fault-tolerant condition can make an aeroengine possess integrity against both sensor failure and parameter perturbation of the engine model. According to the proposed robust fault-tolerant condition,a new design method and an iterative design procedure are presented through increasing gradually the state-weighted matrix in the Riccati equation. The design method was applied to a turbojet engine to demonstrate its effectiveness. It is proved to be very useful and effective with the satisfactory numerical simulation results of the robust fault-tolerant engine control system. The similar fault-tolerant condition and corresponding design method are also concluded in the case of actuator failure.