With the development of global informatization, the big data era has come. Electric power industry is closely related to the national economy and people’s life, so it is necessary to introduce big data to improve its economy and reliability. The establishment of electricity information acquisition system and the accumulation of history information in marketing system provide a rich data fundamental for electric power big data research. Jiangsu Electric Power CO.LTD has advantages and necessity to make full use of electricity big data to carry out related research work. This paper established power load and electricity impact model of different area and industries based on electricity big data, and carried out the research on medium-long term load forecasting, which achieved some results and promoted the application of big data technology in Jiangsu Electric Power Grid.