Abstract: A novel tracking differentiator with high stability and rapidity was studied to quickly track the object signal and correctly resolve its differentiation,which was applied to control the attitude of the non-stationary antenna.A novel non-smooth controller of the second system with a bounded disturbance was proposed;its stability,rapid convergence and strong disturbance rejection ability were studied.A novel tracking differentiator with high stability and rapidity (HSSTD) was proposed with the help of the non-smooth controller and a nonlinear tracking differentiator,its stability is proved in theory.Experiments validate the tracking differentiator can quickly track the object signal and correctly resolve its differentiation.The novel tracking differentiator is been applied in the attitude PID control of non-stationary antenna.Experiments prove the novel tracking differentiator can help the non-stationary antenna to track the target satellite quickly and stablely and ensure communication with a high quality.