The invention relates to a comprehensive energy project economy evaluation method and a comprehensive energy project economy evaluation system. The method comprises the following steps: determining evaluation indexes of a to-be-evaluated project, the evaluation indexes comprising a plurality of first-level indexes, each first-level index comprising a plurality of second-level indexes, and the first-level indexes comprising an investment cost U1, a park matching degree U2, an economic benefit U3 and an environment integrating degree U4; inputting the evaluation indexes into a pre-established investment benefit evaluation model, wherein the investment benefit evaluation model comprises the weight of each evaluation index; and calculating a gray evaluation vector through the investment benefit evaluation model and the whitening weight function for evaluating the gray, determining the gray level of the gray evaluation weight vector according to the maximum weight principle, and determiningthe economy of the project according to the gray level. By utilizing the comprehensive energy project economy evaluation method and system, the comprehensive energy project economy benefit can be scientifically and reasonably evaluated.