Nowadays, many fault tolerance navigation methods have been proposed to improve the flight safety. Those methods mainly concern about the faults of GPS, magnetic sensor, and barometer. In this paper, a novel navigation scheme for quadrotors is designed for IMU fault. In the scheme, a dynamic model/ GPS/ magnetic sensor/ barometer integrated navigation system is constructed. Compared with the traditional scheme, the IMU is replaced by the dynamic model. The dynamic model of the quadrotor is used as a virtual sensor, outputting the angular acceleration and velocity acceleration. Simulations are carried out to verify the proposed scheme, showing that the dynamic model can perform as an alternate sensor of the IMU.