The invention provides an aircraft attitude control method, a system, a medium and a device, wherein the method comprises the following steps: establishing a sliding hyperplane and a sliding mode approaching law according to attitude tracking errors, control law parameters and approaching law parameters; establishing an expansion state observer, and using the expansion state observer to estimate atotal uncertainty in a mathematical model of an aircraft; obtaining an attitude control law according to the sliding hyperplane, the sliding mode approaching law, and the expansion state observer; and controlling the attitude of the aircraft according to the attitude control law. The aircraft attitude control method, the system, the medium and the device can avoid singular problems caused by thetraditional terminal sliding mode control method according to an improved sliding mode control of a fast non-singular terminal, which have a higher convergence rate that can converge errors more quickly in comparison with the traditional non-singular terminal sliding mode control. In addition, by combining the expansion state observer, discontinuous term gains can be reduced, sliding mode chattering can be weakened, and the robustness of the system can be improved through interference estimation and compensation.