Due to the opening of the electricity retailing market, the competitive electricity retailing market allows users choose any electricity company to provide electricity and corresponding services, which will cause the loss of customers and reduce market share of power utilities. At the same time, with the sustainable development of the modern hightechnology industries, the loss and impact of the power quality disturbance of users are continuous increasing. Therefore, power companies have necessary to provide highquality service that meets customer's requirements to effectively attract customers and improve market competitiveness. However, there is a lack of customer classification method considering the demand of both power company and electricity user, which hinders the development of highquality power service. In this paper, a new classification index system of premium users is proposed by considering the lifetime value and power quality demand of users, which combining the comprehensive demand of power grid companies and users. Then, the fuzzy theory is adopted to achieve data standardization, an improved kmeans clustering algorithm is proposed to classify the massive user index data, and the fuzzy AHP based on entropy weight is used to calculate the index weight. Finally, the numerical results show that the evaluation information contained in this method is more comprehensive, which weakens the subjectivity of the general method, and make the result classification results of highquality user more objective and reasonable.