Abstract: Northeast China has the largest high-latitude permafrost distribution regions in China. With the intensification of global warming, carbon stored in permafrost will gradually thaw and release in the form of methane gas, thereby increasing the concentration of methane in the troposphere. However, studies on changes in the methane concentration and release sources in the near-surface troposphere of this region are currently unclear. This paper analyzes the spatiotemporal distribution and change trend of the tropospheric methane concentration across China from 2003 to 2022 using the remote sensing data of Atmospheric InfraredSounder from Aqua satellite and studies the source and mechanism of surface methane release in the permafrost region of Northeast China in combination with the national meteorological and field monitoring data. Results show that the permafrost regions in Northeast China has a high methane release capacity in the four seasons, and the methane concentration presents a significant double-peak seasonal variation feature. The first peak appears in summer (June–August), where the maximum is observed in August. The second peak appears in winter (December–February), where the maximum is noticed in December. The maximum average growth rate of the tropospheric methane concentration in Northeast China appears in spring (the average value is 6.05 ppb/a, 1 ppb=10^－9) because the carbon stored under the frozen layer is gradually exposed and released in the form of methane after the degradation of permafrost. In addition to microbial action, geological methane (metastable methane hydrate, steady-state methane hydrate, and thermogenic methane produced in deep underground or coal seams) stored in the frozen layer of permafrost regions is gradually released. Finally, based on field monitoring results, the thermal gas–solid coupling model of geological methane in the permafrost region is presented, which provides data and technical support for the study of the carbon cycle in the permafrost region in Northeast China.