Based on the equilibrium-manifold-model, a sensor failure diagnosis and fault tolerant control system for a turbofan engine was investigated. First, the equilibrium manifold modeling method was adopted to get the equilibrium-manifold-model for a turbofan engine with approving precision and real time performance. Then, this turbofan model was used as an estimator for sensor output, and to accommodate the failure sensor failure, thus a fault tolerant control system for the turbofan engine sensors was designed. At last, the sensor fault tolerant control process for some typical sensor failures was simulated, and the results illustrated that this method could effectively detect, isolate and accommodate sensor failures.