To address the issues of external disturbances and model uncertainties during the flight of a quadrotor UAV,an Active Disturbance Rejection Control (ADRC) method is adopted to realize attitude control.Meanwhile,improvements are made to the ADRC.Considering that the error gain in the Extended State Observer (ESO) is too large,which is prone to generate oscillations due to error switching,a nfal function is constructed to replace the fal function to achieve a balance between disturbance rejection and oscillation suppression.Additionally,genetic algorithm is used to tune the parameters of the ADRC,which improves the efficiency of parameter tuning.In the simulation system,it is proved that the improved ADRC method exhibits improved disturbance rejection performance to some extent.The effectiveness of the control method is verified on a Hardware-in-the-Loop (HIL) experimental platform for UAV flight control based on a Links-RT real-time simulation system.