The invention relates to a technical supervision system for a grid-connected power plant. The technical supervision system comprises a technical supervision platform and a webpage server. The technical supervision platform comprises the components of a document management module which is used for managing technical supervision quality evaluation standard lists, technical reports, notification files and technical supervision documents; a technical supervision module which is used for managing professional evaluations, comprehensive evaluations and evaluation results; a quality evaluation module which is used for managing summer peak inspection, closed-loop inspection and special inspection; a basis data module which is used for managing basic data of the system; and a system management module which is used for managing and configuring parameter, function and authority of the system; wherein the webpage server displays each module of the technical supervision platform on the webpage in a functional button interface form. Compared with the prior art, the technical supervision system is used as an in-time communication network platform between personnel of power technical supervision execution organization and personnel of each power plant and can realize online technical supervision quality evaluation on the grid-connected power plant. Furthermore the technical supervision system has advantages of high real-time performance, high convenience, high normalization, etc.