To solve the problems of large fluctuation of renewable energy output, low utilization efficiency of renewable energy and energy storage in traditional methods, a multi-scenario optimal allocation method of energy storage in distribution network system considering high proportion of renewable energy is proposed. By connecting energy storage to the power supply side of the distribution network system, the energy storage configuration scenario of the distribution network system is defined. The first-order low-pass filter is adopted, and the expected value of volatility is determined. The time constant of low-pass filter is taken as the key parameter of energy storage capacity configuration, and the energy storage target output power in the fluctuation scenario of energy generation is calculated. The upper and lower limit constraint method is adopted to calculate the output power of the energy storage target in the load energy storage and energy release scenario. Combined with the operation cost of distribution network system, the multi scenario optimal allocation model of energy storage is constructed, the optimal power and capacity of energy storage are solved, and the optimal allocation scheme of energy storage is obtained. The experimental results show that after the optimization of the design method, the maximum fluctuation and maximum fluctuation rate of wind power output and photovoltaic output are reduced, the renewable energy output is more stable, the wind rejection rate and light rejection rate are reduced, the energy storage output is increased, and the energy and energy storage utilization efficiency are improved.