The growing number of cloud services has made service selection a challenging decision-making problem by offering wide ranging choices for cloud service consumers. This necessitates the use of appropriate decision making methodologies to assist a decision maker in selecting the service that best fulfills the user's requirements. In this paper, we present a cloud service description form of quality of service, and present a cloud service selection methodology. The method of ELECTRE is introduced, which establishes the consistency matrix and the contradiction matrix to obtain the priority relation of each service. Finally,the algorithm is verified by an example.