This paper is to clarify the effects of straw and organic fertilizer with alternate application method and amount on black soil physical and chemical characteristics and the community structure of bacteria and fungi.In 2017～2018，“Organic fertilizer →Straw”(AB)，“Straw→Organic fertilizer”(BA)mode were designed，each mode consisted of three gradients(organic fertilizer 15000，30000，45000 kg/hm²；straw 9000，12000，15000 kg/hm²)，no straw，organic fertilizer as the control(CK)， to a total of 7 treatments，to research the changes of soil moisture content，temperature，density，compactness，graded，pH，EC.The maize rhizosphere bacteria and fungi flora characteristics was analyzed using high-throughput sequencing technology.The results showed that:alternation straw and organic fertilizer reduced the bulk density and soil compactness of 0～20 cm soil layer，and the AB model was better than the BA model.The AB model significantly reduces 0～20 cm soil layer temperature，while the BA model increased 0～20 cm soil layer temperature.Straw and organic fertilizer could be used alternately to improve the condition of soil aggregates，reduce the content of large aggregates in soil≥0.25 mm，and optimize the physical structure of soil.The diversity of soil fungal community was significantly reduced by the alternate application of straw and organic fertilizer at the medium amount.The application patterns of organic fertilizer and straw significantly affected the structure of soil microbial community.Soil bulk density，compactness and pH were the main factors affecting the soil bacterial community under the alternate application of organic fertilizer and straw，while fungi were greatly affected by soil temperature，pH and compactness.Compared with CK，each treatment improved the relative abundance of Proteobacteria，Saccharinbacteria and Bacteroidetes，reduced the relative abundance of Nitrospirae，and the AB model had the best performance.In terms of fungi，the relative abundance of Basidiomycetes was increased and the relative abundance of Ascomycetes was decreased by AB treatments compared with CK treatments.At the same time，studies have shown that increasing the application amount of organic fertilizer and straw can increase the relative abundance of Mortierellomycota.