Soil salinization seriously affected soil nutrient utilization and productivity improvement.In order to clarify the effects of different nitrogen application rates and microbial fertilizer on soil salinity，nitrogen absorption and utilization of sunflower and yield in saline-alkali soil，this study took moderately salinized soil in Hetao Irrigation District as the research object，field experiments were carried out with two factors of microbial fertilizer and nitrogen application rate，the microbial fertilizer treatments included A1(7.5 t/hm²)and A0(without microbial fertilizer)，nitrogen application rate were 0(N0)，210(N1)and 420 kg/hm²(N2).The results showed that:(1)Low nitrogen significantly reduced soil electrical conductivity.The soil electrical conductivity of low nitrogen treatment was 0.5-0.8 dS/m and 0.7-1.2 dS/m lower than that of no nitrogen application and high nitrogen treatment，respectively.High nitrogen significantly increased soil pH，and the pH of high nitrogen treatment was 0.2-0.3 higher than that of no nitrogen treatment.The soil pH and electrical conductivity decreased with the application of microbial fertilizer.Compared with the treatment without microbial fertilizer，the application of microbial fertilizer significantly reduced the soil electrical conductivity of high nitrogen treatment.(2)The grain yield of low nitrogen treatment increased by 49.3%-72.6% and 6.1%-8.9% compared with that of no nitrogen and high nitrogen treatment.The grain yield of low nitrogen combined with microbial fertilizer was the best，which was 4695.0-4855.1 kg/hm².(3)Nitrogen application promoted the absorption of nitrogen by sunflower plants.After reaching a certain nitrogen application level，the absorption effect of nitrogen fertilizer plants on nitrogen was not significant，and the utilization efficiency of nitrogen fertilizer decreased with the increase of nitrogen application rate.The application of microbial fertilizer significantly increased the nitrogen content of plants without nitrogen application，and the low nitrogen combined with microbial fertilizer significantly increased the nitrogen use efficiency.(4)Compared with high nitrogen treatment，low nitrogen treatment reduced nitrogen loss by 175.7-177.7 kg/hm²，and the addition of microbial fertilizer further reduced nitrogen loss by 19.9%-34.2%.In summary，combined with soil desalination and crop yield，nitrogen use efficiency and nitrogen apparent balance，microbial fertilizer combined with 210 kg/hm² nitrogen application rate was a suitable fertilization method for farmland in moderate salinization and similar areas in the northwest inland.