In the context of peak carbon neutrality and rapidly increasing demand for electricity，renewable energy is developing rapidly. Renewable energy generation with photovoltaic，wind power and other new energy as the main body is vulnerable to environmental factors，the contradiction between ensuring supply during peak hours and ensuring consumption during low hours is becoming increasingly prominent. During the summer load peak，the wind power output is less，and the photovoltaic evening peak output is basically zero. In the case of the surge of high temperature power load and the regulation capacity of the power grid itself has reached the limit，the greater randomness，volatility and intermittence of new energy will further affect the stability of the power system. This paper analyzes the impact of the increasing proportion of renewable energy on the stability of power system. At last，the countermeasures of the power system are put forward，which mainly include the establishment of accurate power system supply and demand forecasting system，the construction of energy Internet to promote the consumption of a high proportion of new energy，the improvement of the flexibility of the power system and the establishment of electricity marketization mechanism to adapt to the new power system.