Abstract: In response to the problem of large voltage and power fluctuations and poor system stability in the practice of power system stability under large-scale new energy integration, this paper proposes a study on power system stability under large-scale new energy integration. Establish an objective function with the goal of minimizing the power margin of the power system and the amount of new energy waste, and set constraints on the line power range and the DC voltage range of the power system to establish a mathematical model for power system stability. Using multi-objective particle swarm optimization algorithm, by dynamically matching the load demand of the power system with the characteristics of large-scale new energy integration, the solution of power system stability strategy under multiple time scales is achieved, and the power system stability under large-scale new energy integration is achieved based on the algorithm output. Experimental results have shown that under the application of the design method, there are no abnormal fluctuations in the voltage and power of the power system, and the system stability is good, which can achieve stable operation of the power system under large-scale new energy integration.