This paper proposes a theory of parafoil flight trajectory tracking control based on switching systems, which adopts a control method of switching between linear active disturbance rejection control and proportional integral derivative controller. The linear active disturbance rejection control has fast response speed and strong anti-interference ability, and the proportional integral derivative controller relies on error signals to achieve basic control. Switching control is adopted to track and control the azimuth angle of a given reference trajectory; in the switching system, it is determined whether to switch to the corresponding controller based on whether the given reference trajectory is a straight flight, whether the given turning radius of the flight trajectory changes, and so on. The simulation results show that compared with any single control, the switching system has more advantages and better tracking control performance on the flight trajectory.