Financial cost benefit (investment yield, financial net present value, benefit-cost ratio), social and economic benefits (saving rate of medical cost, average household income rate of trained farmers), technical and economic benefits (toilet-flushing water saves, pests and disease reduce rate, fruit or vegetable increase rate, and improve rate of technical skill level), and ecological and economic benefits (saving rate of afforestation cost, reduction of CO2 discharge, reduction of SO2 discharge, soil improvement, fertilizer saving rate) are selected. According to the original survey data of eco-campus economic benefits with 3 different models, Principal Component Projection is used to discuss the calculation method for evaluation index weight of economic benefits in northwest rural eco-campus, and to establish the principal component projection model of eco-campus economic benefits after the normalization processing of index value by efficiency coefficient transformation method based on dimensionless treatment of matrix element. Result shows that from the aspect of financial cost, economic benefits of three eco-campus modes are insignificant. Both ecological benefits and economic benefits are achieved at the same time. According to the overall evaluation results of Principal Component Projection Model, the “Pig, Toilet-Biogas-Vegetable” mode has obtained the maximum economic benefits, followed by the “Grass–Sheep, Toilet-Biogas-Fruit”. And the “Toilet-Biogas-Vegetable” has the poorest economic benefits. This result is of strong practical significance and provides a theoretical basis for economic evaluation research and extension of eco-campus construction in rural primary and secondary schools in other areas of China.