The evaluation of power plant grid-connected operation and auxiliary services has realized the unified and flexible management of grid-connected operation assessment and auxiliary services compensation through the establishment of evaluation model. The evaluation system has enhanced the fair, just and open management for power plant via economic means and improved the accuracy and intelligence of power grid dispatching. Functions are realized in the system of assessment management, auxiliary services, model management, billing management, data integration, information distribution, and system management etc. The system adopts intelligent fault-tolerant and correction technology to automatically identify and process the bad data during massive data calculation and solves the problems of large amount of data and messy types.