The substitution of organic fertilizers for chemical fertilizers is of great practical significance for improving soil quality and improving rural and agricultural production environments.This study analyzed the effects of different ratios of organic fertilizers instead of chemical fertilizers on black soil microbial biomass carbon and nitrogen，soil enzyme activities，and spring wheat grain yield and quality，and explored the appropriate ratio of organic fertilizers to replace chemical fertilizers in this area.Five treatments were set up:no fertilizer(CK)； 100% chemical fertilizer(100%NPK)； 25% organic fertilizer+75% chemical fertilizer(25%M)；50% organic fertilizer+50% chemical fertilizer(50%M)； 100% organic fertilizer(100%M)，the ratio of organic replacement to inorganic was calculated based on the amount of nitrogen，i.e.organic nitrogen replaced 25%，50% and 100% of chemical fertilizer nitrogen.Soil samples(0～20 cm)and wheat grain samples were collected during the spring wheat harvest in August 2019，and soil biological fertility indicators were measured and analyzed，and indicators such as wheat grain yield and quality were analyzed for comprehensive evaluation.1)The differences in soil microbial biomass among different fertilization treatments were different.The microbial biomass carbon and nitrogen reached the maximum in 25%M treatment.Compared with CK，the soil microbial biomass carbon and nitrogen increased by 9.67% and 28.64%，respectively.The combined application of appropriate organic and inorganic fertilizers can keep the biomass of soil microbes in high level.2)Different fertilization treatments had significant effects on soil enzyme activities.Compared with CK，each fertilization treatment soil β-glucosidase，β-cellobiosidase，acetylglucosaminidase，acid phosphatase and leucine amino peptide enzyme activities were improved to varying degrees，of which the full amount of organic fertilizer and 25% organic replacement fertilization treatment significantly improved soil enzyme activities.3)In terms of wheat grain yield，there were significant differences between treatments.Compared with CK，the yield of each fertilization treatment increased by 0.82%～24.34%.The two treatments of 100%NPK and 25% M had the highest grain yield，and the difference was not significant.The crop nitrogen fertilizer agronomic efficiency and nitrogen partial productivity were consistent with the response of wheat yield to different fertilization treatments.The quality of wheat grain，flour and dough was the highest in 100%NPK treatment.Organic fertilizer treatment(25%M，50%M and 100%M)improved most of the indexes of wheat grain quality and dough quality，and reached the high-quality medium gluten or strong gluten standard for wheat.4)Through the analysis of the economic benefits of each treatment，from the perspective of increasing grain production，25%M treatment had the smallest input-output ratio，and improved the utilization of fertilizer resources，increased wheat production，and optimized the allocation of agricultural resources.A comprehensive analysis of the three treatments with different ratios of organic fertilizers to chemical fertilizers，25%M treatment has a good effect in improving soil biological activity，increasing spring wheat yield and improving quality，and at the same time can improve nitrogen fertilizer agronomic efficiency and partial productivity，increase economic benefits.