Distribution network equipment has the characteristics of multiple types and wide distribution, and the factors that advance its decommissioning are difficult to be identified. In order to get the important factors affecting the early decommissioning of equipment, this paper proposed a correlation analysis algorithm, which introduced the three-dimensional matrix into Apriori algorithm, operating more efficiency by reducing the computational redundancy in the classical algorithm, and digs out the set of important factors affecting the early decommissioning of distribution network equipment. By comparing the experimental results, it can be seen that the three-dimensional matrix algorithm can obtain the association rules of distribution network equipment decommissioning factors and significantly improve the computational efficiency.