The invention relates to an electricity quality evaluation system and an electricity quality evaluation method. In order to solve the problem that the electricity quality evaluation cannot be provided according to the user requirement in the prior art, the invention provides the electricity quality evaluation system and the electricity quality evaluation method. The electricity quality evaluation method comprises that: a user inputs the requirement information on a specific electricity quality index; a system end transmits the instruction information to an electricity quality monitoring device of a corresponding electricity quality monitoring point; and the system end performs calculation according to the specific electricity quality index parameter which is uploaded by the electricity quality monitoring device to acquire the electricity quality grade information required by the user. The electricity quality evaluation system and the electricity quality evaluation method have the advantages that: a power supply department can comprehensively and systematically survey the comprehensive situation of the electricity quality in the governed areas and further perform customized evaluation on different types of users (sensitive type and contaminative type) so as to meet the diversified requirements on different types of users.