The invention discloses a lift model-assisted four-rotor aircraft height fault-tolerant estimation method. The method comprises 1, acquiring a lift coefficient of a four-rotor aircraft lift model through a flight experiment, 2, carrying out navigation filtering through two federated Kalman filters in parallel, 3, detecting faults of a four-rotor aircraft height sensor in a navigation filtering process through a fault detection strategy and 4, if the fault of the four-rotor aircraft height sensor is detected, carrying out fault isolation and recovery of the sensor with fault and eliminating thenavigation information of the fault sensor. Through combination of the four-rotor aircraft lift model and airborne sensor, the redundancy of the four-rotor aircraft height sensor is formed, the faultdiagnosis and fault tolerance of the height sensor are realized and the robustness of the navigation system is improved.