The invention discloses an electrical energy quality monitoring and evaluating system, which comprises a plurality of electrical energy monitors, a communication network, a plurality of enterprise service platforms and a government service platform, wherein the enterprise electrical energy monitors are connected to the enterprise service platforms through the communication network, and the independent electrical energy monitors and the enterprise service platforms are connected with the government service platform through the communication network; the enterprise service platforms are used for receiving basic electric power parameters acquired by the enterprise electrical energy monitors at monitoring points inside the enterprises, displaying the change conditions of the electric power parameters of enterprise distribution networks, and transmitting data to the government service platform at certain time intervals; and the government service platform is used for receiving the electricpower parameters of the enterprise distribution networks transmitted by the enterprise service platforms and the parameters transmitted by the independent electrical energy monitors at the monitoringpoints in the regional distribution networks, and performing energy consumption audit, transient and stable electrical energy quality analysis, electrical energy quality level evaluation, harm extentevaluation and evaluation of providing the corresponding electrical energy quality improvement scheme and electrical energy quality improvement effect.