Abstract The large disturbance attenuation problem of the single machine infinite bus system with static synchronous compensator is considered based on the backstepping method. A new minimax disturbance attenuation method is proposed based on the maximization of the external disturbances, and it is used to reduce effectively the conservativeness of the disturbance attenuation, which is brought by the estimation of the upper bound of the disturbance and the inequality scaling. The purpose is to ensure the good robustness and insensitivity to large disturbances of the STATCOM system. The single-machine infinite-bus system with the short-circuit ground fault and the mechanical power disturbances is researched. Simulation results show that the control scheme can effectively improve the dynamic process of the transient stability of the power system. Compared with the conventional nonlinear controller, the control scheme has more advantages for large disturbances, and the process of controller design is simple and intuitive.