It is easy for a power system to be affected by disturbance and it will enter a chaotic state under certain disturbance conditions. A bifurcation diagram and the Lyapunov exponential spectrum are used to analyze the influence of perturbation Pe and Pk on the power system when they act alone or together. When Pe and Pk act alone, the system states transition from the periodic state to a chaotic state with the increase of perturbation. When Pe and Pk act together, with the increase of the disturbance, the system states transition from the chaotic state to a periodic state and then back to a chaotic state. This paper designs a kind of global sliding mode control with time-delay strategy. The time delay control uses a delay feedback loop, namely the error signal using the sampling value of the sampling period and the sampling value of uncertain systems are estimated with the disturbance. However, because of the delay link lag error, this results in slow convergence speed and lower ability to reject disturbance. For this reason, the time delay control is combined with global sliding mode control, and a time delay compensation term with fast convergence is designed to improve the convergence speed and anti-disturbance ability of the system. This also suppresses the external disturbance whose upper bound is unknown. The simulation results show that compared with the time-delay control, the proposed global sliding mode time-delay control has faster convergence speed and less overshooting, and can still guarantee convergence when the system is subjected to periodic and step disturbance. This work is supported by the National Natural Science Foundation of China (No. 61803233).