In order to improve the effect of user access control in the power marketing system, a power marketing system user authority distribution method based on role based access control model is proposed. Trust attribute is used to extend the access strategy expression, obtain the global trust of the information resources of the power marketing system by monitoring the user’s access behavior, and control the access authority. According to the access authority control result, based on analyzing the autonomous access control model and mandatory access control. On the basis of RBAC model, and the concept of role is introduced. By quantitatively calculating the trust of different access behaviors among users in the assignment of permissions, the access level of user permissions is obtained, and the power marketing system is completed. The experimental results show that the proposed method has shorter user access authority control time and lower user authority allocation error rate, which improves user satisfaction.