Based on the expansion principle and expansion method of CIM for power system,the urban railway transit power supply system is expanded,and the CIM model of urban rail transit power supply system is established based on object-oriented programming technology.Based on the model,the urban railway transit power supply calculation algorithm package is developed as a stand-alone plug-in embedded power monitoring system(PSCADA).As an advanced application of PSCADA,it can realize the function of “plug and play”.Finally,according to the calculation results of the whole network power of a subway line,the CIM model of the urban rail transit power supply system and the correctness of the data import and export under the model standard are verified.