To analyze the development trend of city power backbone communication network in particular stage and determine the key factors restricting the development, it is necessary to make a comprehensive development level diagnosis for the whole communication network. This paper establishes a layered, multi-objective fusion panoramic diagnosis index model for city power backbone communication network from the aspects of the grid development level, backbone communication network development level and backbone communication network topology state with multilevel extension method, and finally obtains the diagnosis results of the communication network development level in the form of grades. According to the established diagnostic index model, three typical cities are the objects of the research to make the comprehensive development diagnosis for these power backbone communication networks during the period of Twelfth Five-Year. In addition, the proposals are also given about the future development focus and the investment. The diagnostic model is provided to offer solutions and ideas for the research of constrction state oriented to the planning and development of city power backbone communication network.