Abstract: Rational classification of electricity market customers can be used as the basis for market access, market regulation and service strategy. Based on the latest development of electricity market reform, a reasonable classification index system is constructed with consideration of the factors such as renewable energy certificate, demand response and load curve. The two-step principal component analysis (PCA) is used for data dimension reduction to eliminate the repeated information between indicators as well as making the clustering result visible. To deal with the flaws of the traditional clustering algorithms that need to specify the parameters, the advanced affinity propagation (AP) clustering algorithm is used to realize customers clustering. A case study of 40 customers is conducted, which has proved the effectiveness and advantages of the proposed model. Finally, the regulatory design of survival of the fittest is introduced, and suggestions are put forward for customer admittance and management in the electricity market, which are of practical value.