Abstract:The secondary system of intelligent substation generally adopts the network architecture of three layers and two networks, which uses the merging unit and the intelligent terminal to complete point-to-point sampling and tripping respectively. The merging unit and optical module are widely used, so the sampling reliability cannot be guaranteed. At the same time, the secondary information transmission is classified according to functions and transmitted independently through different systems, with low degree of information fusion, it is difficult for every business department to obtain data, and the information transmission cannot provide effective support for every business department of the power grid. Therefore, the original three-layer and two-network networking scheme was optimized in the networking scheme, and cable sampling and GOOSE network tripping were adopted to replace the direct sampling of SV and GOOSE tripping. In terms of the way of information transmission, professional barriers should be broken, information transmission should be reorganized according to business needs, and information fusion should be vigorously promoted to realize data sharing. At the same time, puts forward the key technologies to be solved in the optimization scheme, analyzes the feasibility of the promotion and implementation of the new scheme, and draws the conclusion that the new scheme is simple in construction, convenient in maintenance, reliable in operation and convenient in management through comparative analysis.