The role-based access control（RBAC） is an extensively researched demand-oriented enterprise security access control strategy with the most mature thinking. On the basis of core-RBAC model， roles set and permissions set are fractionized. The fractionized core-RBAC model is finer in permissions setting. In accordance with the actual needs of administrators， each one can definitely set the functions and permissions of role in the five dimensions， i.e. data cycle， data object， data sort， operation function， operation level， and deep and flexibly control the functions of role and the visited data content to achieve accurate management. Moreover， the refinement RBAC model is used in the development of competence management module of the power supply ERP system， and a good application effect is achieved.