Abstract: To promote the identity standardization for the power market subjects, the creation of a unified identity model has positive effects on the construction of the national unified power market system. In addition, this unified identity model is conducive to enhancing the operational efficiency of the power market and perfecting the power market mechanism adapting to the novel power system. This paper contributes in the following four aspects. (1) The analyzation of the significance and the main points in designing the unified identity model for the market subjects. (2) The proposal of a multi-level model for the multi-market and multi-role market in the future, in which the data composition of each level and the data association characteristics among the models are analyzed. (3) The elaboration of the concept of the whole life cycle management of the market subjects based on the unified identity model and the summarization of the key points in the model's application in accordance with the engineering practice. (4) The introduction of the unified identity service platform in the power market in Yunnan province constructed based on this unified identity model. The implementation results of the service platform in Yunnan province verifies the effectiveness of the model proposed here.