In order to realize the modernization of electric power marketing business, convert the information’s transmission , and improve the management level of customer file information, this paper has developed the power marketing customer file management system. Firstly, based on the B/S model, the power marketing customer file management system was designed. Second, K  means algorithm was put forward, in the classification of computing, introducing weighting factor for each data and individual data center weighted distance, improved its classification accuracy is demonstrated by the simulation experiment, and applied to the customer file data statistics and analysis; Finally, in this paper, the development of electric power marketing customer file management system, running on the national grid for actual test, the test results show that this system has realized the basic functions, and fast response, high processing efficiency.