The large amount of pollutants emitted by coal heating in winter is one of the main causes of haze, which brings great trouble to people’s lives. To reduce air pollution caused by coal burning and improve air quality, the state advocates the transformation of traditional electric heating methods to accelerate the transformation of China’s energy system to a clean and low-carbon model and improve the utilization rate of renewable energy in China. Therefore, this article through the calculation of the residual capacity of the retrofit and the calculation of the air conditioning load to assist the electric heating transformation. Firstly, the average power of the transformer during a high power period is calculated instead of taking the maximum power directly, which solves the problem of small residual capacity caused by a large maximum load rate and maximizes the transformable capacity. Secondly, the cluster analysis of air conditioning heating as one of the typical electric heating methods is carried out by the K-means clustering method, and the air conditioning load is obtained as the data reference during the electric heating transformation to assist the optimization transformation of electric heating. The two methods are further studied and verified by two examples, and the theory guides the practice to assist the electric heating transformation and achieve the goal of energy saving and emission reduction.