The present invention relates to a comprehensive evaluation system for power grid development diagnosis. The system is characterized by comprising: a data fusion module. The data fusion module extracts information from a multi-source database and sets up a power grid diagnosis analysis data pool by categories, and an indicator calculation module calculates a power grid development indicator; and calculated data is transmitted to a diagnosis evaluation module, and the data of the diagnosis evaluation module is diagnosed by a weakness warning module, so as to put forward diagnosis opinions and prevention and control measures. The system provided by the present invention realizes informationization of indicator calculation of power grid development diagnosis, and automatically diagnoses the weakness of power grid development, so that the system is of significance for guiding precise planning of the power grid and has excellent actual application prospects.