The objective was to investigate the effects of different microalgae organic fertilizers on the growth， yield and quality of tomato.Through the principal components analysis and evaluation scores of effects of different micro algae organic water-soluble fertilizers，an analytical method and theoretical basis were provided to evaluate the quality and achieve high yield and quality. Three microalgae organic water-soluble fertilizers were selected，and explored the improvement effect of different microalgae organic water-soluble fertilizers on tomato yield and quality through a 2-year of field experiment.The results showed that:(1)The yield of tomato treated with microalgae organic water-soluble fertilizer was significantly higher than that of the water control treatment.Under the same amount of conventional fertilization conditions，the single fruit weight of the treatment treated with three types of microalgae organic water-soluble fertilizers(Competitor，Algafert，Levoamin)was significantly increased，and the yield was increased by 4.87，6.86，5.46 t/hm²，respectively.(2)Compared with conventional fertilization control and clear water control，the nitrate and organic acid content of the three microalgae organic water-soluble fertilizers were significantly decreased，while the content of soluble solids and vitamin C were significantly increased.(3)From the analysis of principal component comprehensive scores，the treatment using Algafert scored the highest，followed by Levoamin and Competitor.Taking into account factors such as plant height，stem diameter，yield and quality of tomatoes，the microalgae organic water-soluble with the best application effect on tomatoes was Algafert.