Abstract: The intelligent substation adopts a dual configuration of intelligent terminals, which not only improves the reliability of protection, but also hinders the correct operation of the reclosing interlocking circuit. Therefore, this article deeply analyzes its mechanism and root causes, and proposes improvement measures based on hard node series connection. This article introduces a hard wired AND gate logic in series in the interlocking reclosing circuit of two sets of intelligent terminals, optimizes the communication configuration, establishes a cross terminal status monitoring mechanism, and adds a dual terminal collaborative signal testing link. The actual engineering experimental results show that the improvement measures proposed in this paper can effectively eliminate the hidden danger of reclosing misoperation caused by a single terminal fault, significantly improving the reliability and safety of the reclosing circuit in intelligent substations.