In this paper，the effects of long-term application of nitrogen and phosphorus fertilizers on soil respiration component characteristics and carbon balance were explored，which could provide a reference for improving the carbon sequestration efficiency of farmland. The field experiment was set up in 2017，using a randomized block experimental design，with spring wheat as the test crop，and four treatments，namely control(CK，no fertilization)，nitrogen fertilizer(N，N 115 kg·hm-2)，phosphate fertilizer application( P，P2O5 115 kg·hm-2)，and combined nitrogen and phosphorus application(NP，N 115 kg·hm-2 and P2O5 115 kg·hm-2)，and the characteristics of soil respiration and emission during the growth period of 2021 and 2023 were measured by static box-gas chromatograph. The relationship between soil enzymes and microbial biomass carbon and soil respiration was investigated，and the soil carbon balance of nitrogen and phosphorus fertilizer application was analyzed. The results showed that in the two growing seasons，soil respiration and autotrophic respiration showed a bimodal trend with time，and heterotrophic respiration showed a unimodal trend during the growth period of spring wheat，which was the largest at the flowering stage，the results in 2021 and 2023 were as follows:NP trentment(6405.12 and 6150.27 kg·hm-2)> P trentment(5667.53 and 5423.97 kg·hm-2)>N trentment(5626.58 and 4630.82 kg·hm-2)>CK trentment(4366.67 and 4128.29 kg·hm-2). Compared with soil moisture，soil temperature could better explain the change of soil respiration rate(53.6%-68.1%)，and random forest and structural equation models showed that soil available phosphorus，organic carbon，microbial biomass carbon，polyphenol oxidase and cellobiophilia hydrolase were the main influencing factors of soil respiration. The carbon balance of each treatment ecosystem was greater than 0，which was manifested as a“ sink” of soil carbon，and the carbon sequestration potential of NP treatment was the best in the dryland farmland of the Loess Plateau in Longzhong. In general，nitrogen and phosphorus fertilizer application had a significant impact on soil carbon emissions and carbon neutrality of agroecosystems in drylands.