Soil microbial respiration is an important component of the carbon cycle in terrestrial ecosystems, and it is significantly influenced by atmospheric nitrogen deposition. The northern part is a high nitrogen deposition area in China, and it is important to study the response of soil microbial respiration and temperature sensitivity (Q₁₀) to nitrogen deposition in forests in this region. In this study, 7 levels N addition experiment (0, 5, 10, 20, 40, 80, 160 kg N hm^-2 a^-1) was set up to simulate N deposition in a Larix principis-rupprechtii plantation in Northern Yanshan Mountains, and soil samples were collected two years after fertilization and soil respiration culture experiments were conducted at 15 ℃ and 25 ℃. The effects of N application on soil microbial respiration and temperature sensitivity in Larix principis-rupprechtii plantations were investigated by redundancy analysis, structural equation modeling and other methods. The main findings were as follows: (1) The soil microbial respiration rate under 15 ℃ and 25 ℃ cultivation showed a decreasing trend with the increase of nitrogen addition. Compared with the control, the microbial respiration rate under 160 kg N hm^-2 a^-1 treatment decreased by 23.94% and 21.64% at 15 ℃ and 25 ℃, respectively. (2) The range of Q₁₀ was between 2.60 and 4.92, the overall trend was first decreased and then increased with the increase of nitrogen addition, reaching the highest value at 80 kg N hm^-2 a^-1 level of N addition. (3) Redundancy analysis showed that soil non-labile carbon (NLC) and nitrate nitrogen (NO^-₃-N) were the main influencing factors of soil respiration rate after nitrogen addition, and the influencing factors of soil respiration rate were also different at different temperatures. (4) N addition may increase Q₁₀ by increasing the effectiveness of soil N and by changing soil carbon stability. The results of this study showed that nitrogen addition decreased the soil microbial respiration intensity and first decreased and then increased the temperature sensitivity of Larix principis-rupprechtii plantations, which can provide a scientific basis for the study of soil carbon dynamics in forest ecosystems under the background of atmospheric nitrogen deposition.