Abstract: Considering the uncertainty of a linear system and a class of sensor failures including the reduction of sensors gains, the switching-on-off of sensor channels, and the switching-off of sensor channels, a method of robust fault-tolerant using LQR theory was studied. The resulting design guaranteed closed-loop stability and robust performance not only when all sensors are operational, but also in case of some sensors outages. Conclusion and proof were given which ensured that the controller is insensitive to the class of failures. Simulation results identified the validity of the method.