As one of the most widely distributed thermokarst landscape caused by permafrost degradation， thermokarst lake is an important source of methane （CH₄） in the atmosphere. The evolution of thermokarst lakes and its influence on CH₄ cycle are key issues in the study of climate change. In this paper， we reviewed the evolution， distribution and change of thermokarst lakes in permafrost regions of the Northern Hemisphere. CH₄ production， oxidation， and emission from thermokarst lakes and their influencing factors were revealed. The results showed that the areas of thermokarst lakes around the Arctic was approximately 1.6×10⁶ km². Although thermokarst lakes may expand or form in some regions， the overall coverage of thermokarst lakes was decreasing. The area of thermokarst lakes on the Qinghai-Tibet Plateau was 2.83×10³ km²， which showed that the number and area of thermokarst lakes increased significantly in the central region， but these showed a decreasing trend in the source region of the Yellow River. Influenced by the stability of organic matter and microbial community， the rich-organic matter layer in the near-surface and thawing permafrost layer under the thermokarst lake have the great potential for CH₄ production， but the CH₄ oxidation greatly limits the CH₄ emissions. It has been estimated that the CH₄ emissions from thermokarst lakes in the Arctic region ranged from 1.9 to 6.3 Tg CH₄·a^-1 with a large uncertainty. In the future， we need strengthen remote sensing technology to improve the recognition accuracy of thermokarst lake， and focus on the effect of lake drainage on the CH₄ cycle. These will deepen the insight in the support for the prediction of the lake development trend and the assessment of permafrost carbon feedback. In addition， we should pay more attention for the long-term field monitoring in typical and sparse areas， and explore the mechanisms of CH₄ production and oxidation in thermokarst lakes. Finally， the drivers of methane production and emission， such as substrate availability （the amount of organic matter that microorganisms can directly decompose and use）， microbial characteristics， hydro-thermal change and vegetation， should be incorporated into biogeochemical models in the future to better predict and evaluate the contribution of carbon emissions from thermokarst lakes to global warming.