With the construction of smart grid and smart substation, influences of the main electrical connection on the reliability of the entire power gird have become more and more important. Therefore, coordinated development between power grid and substation is a key to the design and optimization of main electrical connection. In this paper, the entire equipment in power grid including the main electrical connection is simulated simultaneously, and then the index of power gird with the main electrical connection optimization by disconnecting circuit breaker is calculated. Optimization schemes are sorted by the method of TOPSIS, realizing the evaluation of main electrical connection based on coordinated development between power grid and substation.