We consider the information sharing, distributed processing and interoperating caused by different Standards and information models in this paper. For various parts of Power Grid such as generation, transmission, transformation and etc. A division method based on automatic control theory is proposed. With the large quantity collection of electric power production, operation and control information, we classify the information to the 4 categories and 12 sub-categories. The Quality Function Deployment (QFD) method is introduced as an innovative usage for evaluating the classification results, which is widely used in the procedure area of production. The division method for the information of power system is proved to be novel and the classification results can be used as the fundamental research of united power information model for further Smart Grid.