According to the Common Information Model IEC61970, which defined all the models for the electronic equipments and topology relationship among them, a network topology for substation’s main wiring based on CIM is proposed. By extracting node to node correlation matrix, the method, simplifying and accelerating the correlation matrix, is used to analyze electrical connectivity, thus analyzing time is shortened and system memory is economized. Experimental results show that the method proposed by this paper can be effective to promote the specifications for substation simulation system designing and the real time in running.