The source servicing in the smart substation offers the base for the model integration between the substation and the main substation. The IEC 61850 Ed.2 provides the base for conversion and share of the information model between the substation and the main substation. The description form, the structure, the function and the characteristics of the SSD(system specification description) model in IEC 61850 Ed.2 and the CIM(common information model) model in IEC 61970 are analyzed. In addition, the difference and characteristics between SSD model and CIM model are compared. As a result, the mapping relation and the common ground are obtained. Furthermore, the conversion technology between SSD model and CIM model is realized, which provides forceful guarantee for data consistency at dispatch centers in source servicing of unified information platform of smart substation, and for the information share between the substation and the main substation.