In order to improve the security of user rights management and authorized access of public security modernized business information query platform in B/S mode, this paper proposes a fine-grained rights management model. The model is based on the principle of role-based access control, based on the original RBAC architecture of the public security system, the FDPC architecture is proposed, and designed for the characteristics of the public security information is complicated, the number of users is large, and the job changes are frequent. Through the “field-level” correspondence between functions and data, it realizes fine-grained decomposition of access rights to resources. In addition, this paper proposes a two-step clustering analysis based on query logs to realize the design of optimal role assignment schemes for specific departments. Through role authorization and direct user authorization, permissions are classified and managed hierarchically, thus greatly enhancing the flexibility and scalability of user rights management in public security operations.