Using the utility theory, on the basis of the tiered electricity price grading model optimized by the rank-sum ratio method, the impact of the ladder electricity price on residents’electricity demand and the income of enterprises’electricity sales is analyzed. According to the average annual disposable income of the residents, the residents are divided into four levels, and the change of the residents’electricity demand after the implementation of the tiered electricity price is analyzed through the utility theory, so as to reveal the influence mechanism of the tiered electricity price on the residents’electricity demand. The electricity sales of the electricity supplier are closely related to the electricity demand of residents, and the selling price will affect the electricity demand of residents. Therefore, it is necessary to combine the changing trend of electricity sales with the selling price, so as to determine the electricity demand of residents and the cost change of the electricity supplier. Through the analysis of the residents’electricity demand and the electricity supplier income after the implementation of the ladder electricity price in a city, the following conclusions are drawn：Firstly, the overall electricity demand of the residents is reduced；Secondly, the electricity demand of low-income groups is guaranteed；Thirdly, the electricity supplier income is also increased, giving consideration to both economic benefits and social security.