Along with the promotion and deepening of the pilot and construction of smart substation in State Grid Corporation, the influence of new smart switch equipment on the main electrical connection in substation will be more and more important in the future, according to the guiding ideology of a new generation of smart substation: ‘highly integrated system, reasonable structural layout, advanced and appropriate equipment, energy conservation and environmental protection, supporting the integration of regulation and control’. Combined with the typical design schemes of 220, 110 kV substations, this paper studied the influence of new smart switch equipment on the main electrical connection in smart substation, which could be the reference for the future construction of smart substation.