How to isolate the relevant secondary equipment safely and reliably from each other in the expansion, renovation, and maintenance of smart substation is a problem to be solved. The digital age is no longer limited to the traditional maintenance methods, analyzes the configuration process of intelligent substation, and proposes a secondary system design. This paper studies the safety measures of secondary maintenance and illustrates the improvement of secondary security measures of intelligent substations through the method of knowledge map, so that the intelligent substation secondary security ticketing system based on knowledge map can be popularized and applied.