The widespread application of airconditioning equipment has brought a large amount of airconditioning load to the power grid, which has an increasing impact on the safe and economic operation of the power system. In order to correctly estimate the airconditioning load scale, this paper proposes a winter airconditioning load calculation method that considers the correlation between temperature and load.Firstly, by calculating the correlation coefficient between temperature and load in the screening process, the abnormal temperature day is excluded from the reference day. Secondly, considering the daily growth of basic load, regression analysis method is used to fit the basic load curve of each day in winter. In view of the characteristics of the rapid decline of the power system load during the Spring Festival, the Spring Festival coefficient is proposed to modify the basic load of the winter base load. The winter airconditioning load is the difference between the winter power system load and the winter base load. This method is used to calculate the airconditioning load in Chongqing in 2018.The results show the effectiveness of the method.