The rapid expansion of substation scale has increased the pressure on operation and inspection personnel, making it difficult for them to detect abnormalities in power equipment in a timely manner when inspecting various equipments in the substation. In response to the above issues, this paper designs a substation power equipment status monitoring system based on association rules. The overall architecture of the system and the software and hardware environment required for system operation are designed. The fuzzy clustering is used to process data collected from substations and distributed systems are utilized to store various types of data. A twin model of the substation is established through surface reconstruction method and the database is designed accordingly. An association rule model and a logical information model are established to describe the actual operation status of the substation. Finally, the feasibility of the system is demonstrated through practical application in a certain city company.