In order to investigate the effects of different irrigation water quality and quantity levels on the quality and yield of greenhouse tomatoes, principal component analysis was conducted for comprehensive evaluation of the effects of three types of water, which were sewage, reclaimed water, and fresh water, and the irrigation amount on the quality and yield of tomatoes. The results show that the accumulative contribution rate of four selected principal components was 89. 70%. There existed significant differences in vitamin C, nitrate, and soluble protein, but insignificant differences in soluble sugar, yield, and irrigation water utilization efficiency with different irrigation water quality and quantity treatments. Under the experimental conditions introduced above, the comprehensive evaluation results of the data handled by the membership function ranking showed that reclaimed water with an irrigation amount of 360 mm was the optimal irrigation condition. Average ranking results of the two sets of data showed that reclaimed water with irrigation amounts of 320 mm and 360 mm had a better effect.