A fast super twisting algorithm is proposed to improve the convergence properties of the super twisting algorithm with increasing the linear term.The convergence properties of the fast super twisting algorithm are investigated by means of the Lyapunov method. The algorithm is applied to the flying wing UAV attitude control system, and a fast super twisting disturbance observer is designed to estimate and compensate for disturbances. Simulation results show that the fast super twisting disturbance observer is faster than the super twisting disturbance observer with the same controller parameters, and
can effectively improve the robustness of the attitude control system.