In view of the wind gusts and unmodeling characteristics in trajectory tracking control of a quadrotor aircrafta new method is presented.This controller is called dual-loop conditional integral sliding mode controllerwhich is based on nonlinear sliding mode control techniqueconditional integral idea and Lyapunov stability theory.The nonlinear dynamic model of the quadrotor is linearized to simplify the mathematical model of the controlled object and improve the efficiency of controller design.The trajectory tracking controllers of position loop and attitude loop are designed by using the conditional integral sliding mode control lawand global asymptotic stability of the control system is realized.The effectiveness of the designed controller is verified by simulation cases.The simulation results show that the controller has higher control accuracystronger anti-interference ability and stronger robustness compared with other controllers.It can effectively suppress system chatteringeliminate static errors and realize high-performance trajectory tracking of a quadrotor aircraft.