Taking the dry farming and no-tillage oat field as the research object, six treatments: no fertilization（CK）,single nitrogen application（N）, single application of phosphate fertilizer（P）, single application of potassium fertilizer（K）, combined application of nitrogen, phosphorus and potassium（NP）, and combined application of nitrogen, phosphorus and potassium（NPK） were set up. Effects of different fertilization treatments on soil nutrients, microbial biomass and oat yield in dry farming and no-tillage field was studied. The results showed that fertilization treatments could increase the soil organic matter, total nutrient and available nutrient content in dry farming and no-tillage oat fields to varying degrees. Soil microbial biomass carbon, nitrogen, and phosphorus in different fertilization treatments increased first and then decreased during the oat growing period, the order of soil microbial biomass carbon and nitrogen was as follows: NPK＞NP＞N＞P＞K＞CK, the order of soil microbial biomass phosphorus level is as follows: NPK＞NP＞P＞N＞K＞CK, and among them, the difference in soil microbial biomass carbon, nitrogen and phosphorus between the NPK and NP and CK reached significant levels. The yield performance of different fertilization treatments was NPK＞NP＞N＞P＞K＞CK. Except for P and K, the other treatments were significantly different from the CK treatment. Among them, NPK had the highest yield, which was 2 238.25 kg/ha, and which is 24.3% higher than the control.