When used in four-rotor aircraft control,the traditional linear discrete sliding mode has the shortcomings of large tracking error,low response speed,and long convergence time.Aiming at the four-rotor aircraft with outside interference,system uncertainties and modeling errors,we proposed a discrete adaptive terminal sliding mode control method based on disturbance observation compensation.First,the terminal sliding mode control law was designed to the discretization equation including the four-rotor aircraft model,and an adaptive law factor was introduced to decrease the chattering.An improved discrete disturbance observer was constructed by taking the square of the state variables as interference error convergence,and its stability was proved.The improved discrete disturbance observer was used to get high-accuracy estimation of the unknown interference,uncertainties and modeling errors,which were used for compensation in controller design.Thus the robustness was increased and the steady-state error was decreased.Finally,the proposed method was used for the control of four-rotor aircraft.Simulation on Matlab shows that:Compared with the discrete terminal sliding mode controlling method,this method has a faster response speed,better tracking effect,and higher robustness,which can implement stable attitude control of the vehicle in the presence of uncertain disturbance.