Objective  In order to solve the obstacles of tomato continuous cropping in solar greenhouse, the effects of combined application of organic and inorganic fertilizers on soil microorganisms of tomato continuous cropping were studied.

  Method  Six treatments were set up: no fertilization (CK), 20% organic fertilizer + 80% chemical fertilizer (M20C80), 40% organic fertilizer + 60% chemical fertilizer (M40C60), 60% organic fertilizer + 40% chemical fertilizer (M60C40), 80% organic fertilizer + 20% chemical fertilizer (M80C20),100% organic fertilizer + 0% chemical fertilizer (M100). The physical and chemical properties of soil, microbial community structure, species composition and abundance of bacteria and fungi were measured.

  Results  The results showed that M40C60 maintained the soil porosity at 54.38%-55.61%, pH at 7.19-7.22, the contents of organic matter and available potassium at 49.70-59.21 g kg⁻¹ and 536.08-605.49 mg kg⁻¹, respectively, and the content of available phosphorus at 680.41-782.96 mg kg⁻¹. Increasing the application of organic fertilizer improved the composition of soil microbial community, and increased the relative abundance of beneficial bacterial communities, such as Bacillus, Terrisporbacter, Streptomyces and Cephalotrichum by 0.86%, 0.60%, 0.12% and 47.82%, respectively. The relative abundance of harmful bacterial communities such as Proteobacteria and Acidobacteriota was reduced by 3.47% and 1.74%.

  Conclusions  Increasing the application of organic fertilizer is beneficial to improve the soil physical and chemical properties under tomato continuous cropping, to maintain the nutrient contents at the same time. It is beneficial to the succession of microbial community, maintain or improve the abundance of beneficial flora, inhibit or reduce the abundance of harmful flora, maintain the continuous cropping soil in a relatively stable microbial community structure and reduce the occurrence of soil diseases under tomato continuous cropping, maintain good soil condition.