Reclaimed land is an important reserve land resource, but usually the soil structure is poor, and the organic matter and nutrient content are low. Increasing the application of organic fertilizers is a key way to quickly improve soil productivity, but it will cause large emissions of greenhouse gases such as nitrous oxide (N₂O). Inoculation with plant rhizosphere growth promoters (PGPR) with N₂O reduction function not only reduces greenhouse gas emissions, but also promotes crop growth. In this study, a PGPR denitrificans YSQ030 with N₂O reduction function was used as the test strain to clarify the effect of inoculation YSQ030 on N₂O emission and nitrogen cycling key functional genes in reclaimed soil with organic fertilizer application. By setting up soil microcosmic experiments for the application of commercial organic fertilizer and sheep manure organic fertilizer, the soil N₂O emission flux after inoculation YSQ030 was analyzed by gas chromatography, and the cumulative emission was further calculated. Soil pH, EC, nitrate nitrogen and ammonium nitrogen content were analyzed at the end of the experiment, and the abundance of soil nitrification functional genes (AOA amoA and AOB amoA) and denitrification functional genes (nirS, nirK, nosZ I and nosZ II) was analyzed by real-time real-time quantitative PRC. The results showed that inoculation of YSQ030 in soil applied to commercial organic fertilizer and sheep manure organic fertilizer significantly reduced the N₂O emission of reclaimed soil, and the maximum reduction of N₂O emission was 90% and 30%, respectively. The N₂O emissions of commercial organic fertilizer treatment were much higher than those of sheep manure organic fertilizer treatment, which may be due to the fact that the abundance of the N₂O reductase gene nosZ I and the nosZ II gene of the N₂O reductase gene of atypical denitrifying bacteria N₂O reductase in the soil applied to commercial organic fertilizer was significantly lower than that of the soil where sheep manure organic fertilizer was applied. The application of commercial organic fertilizer significantly reduced the abundance of functional genes of soil nitrification and denitrification, while the application of sheep manure organic fertilizer had no obvious effect on the abundance of functional genes of soil nitrification and denitrification. This study shows that inoculation with YSQ030 can reduce the N₂O emission in soil applied with organic fertilizer, which will provide a scientific basis for soil fertility improvement and N₂O emission reduction, and will also provide core strain resources for the research and development of new microbial fertilizers or bio-organic fertilizers.