The decline of soil function caused by long-term continuous monoculture in greenhouse is an important factor limiting the sustainable development of tomato industry in China. Pot experiments were conducted in a solar greenhouse to study the effects of different continuous cropping years(0，5 and 20-year)on tomato yield，quality，soil chemical properties，enzyme activities，and microbial community structure and number. Results showed that:tomato continuous cropping increased tomato fruit yield(22.33%～29.88%)，fruit soluble sugar content(43.44%～55.12%)，vitamin C content(6.88%～32.39%)，nitrate content(19.40%～24.42%)and sugar/acid ratio(61.23%～133.92%)，but decreased total acidity(13.51%～35.14%).The soil pH of continuous cropping in 5 and 20-year soils decreased by 0.20 and 1.23，carbon to nitrogen ratio decreased by 6.46% and 8.33%，respectively，compared with that of continuous cropping in 0-year soils. However，the soil electrical conductivity and nutrient content of continuous cropping in 5 and 20-year soils increased by 6.53% and 26.75% compared with that of continuous cropping in 0-year soils. The activities of soil catalase and polyphenol oxidase decreased，while the activities of urease and acid phosphatase increased with the increase of tomato continuous cropping duration. Continuous cropping changed the structure and composition of microbial community in soil. Compared with 0-year soil，there was no significant change in bacterial richness and diversity in the 5-year soil，but they both decreased significantly in the 20-year soil；continuous cropping reduced the fungal richness，and the diversity first decreased and then increased. The bacterial community structure was similar between 0 and 5-year continuous cropping soils，while the fungal community structure between 5 and 20-year continuous cropping soils was similar. Proteobacteria and Gp6 were the bacterial phylum and genus with the highest relative abundance for all the three treatments，respectively；Ascomycota and Ascomycota_unidentified_1_1 were the fungal phylum and genus with the highest relative abundance，respectively. Continuous cropping inhibited the growth of some dominant microorganisms，such as Actinobacteria，Ilumatobacter of Actinobacteria，and fungus Glomeromycota，and also promoted the growth of some dominant microorganisms，such as Gemmatimonadetes，Gemmatimonas of Gemmatimonadetes and the fungus Cladorrhinum. Continuous cropping significantly increased the number of fungi(49.16%～59.22%)and Fusarium oxysporum f. sp. lycopersici(820%～2679%)，and decreased the actinomycetes/fungi ratio. The number of actinomycetes first increased and then decreased with the continuous cropping years. Long-term continuous cropping resulted in reduction of tomato commercial value and soil function.