Under global warming, the increasing frequency of high-temperature events in lakes, combined with the implementation of the "Cessation of Aquaculture and Return to Lake" ecological restoration project in the eastern Lake Taihu region since 2019, has created complex interactions that complicate the dynamic processes of methane (CH4) emissions from lakes. This study aims to elucidate the impacts of high-temperature events and ecological restoration on CH4 emissions in Lake Taihu and their underlying mechanisms. Based on high-frequency observational data from the Dongtaihu site of the Taihu Eddy Flux Network from 2018 to 2020, the seasonal threshold method was employed to identify high-temperature events, and their effects on CH4 fluxes, as well as the regulatory effects of the "Cessation of Aquaculture and Return to Lake" project, were systematically analyzed. The results indicated that the seasonal threshold method effectively captured short-term high-temperature processes driving CH4 emissions, accommodating seasonal water-temperature fluctuations and high-frequency temporal variations in CH4 emissions. A total of 23 high-temperature events were identified from 2018 to 2020. The promoting effect of high-temperature events on CH4 emissions showed clear seasonal differences, being stronger in spring and autumn than in summer and winter. During individual events, CH4 fluxes typically exhibited a three-phase pattern: remaining stable in the pre-heatwave period, increasing sharply during the heatwave, and decreasing in the post-heatwave period. The "Cessation of Aquaculture and Return to Lake" project effectively suppressed CH4 emissions during high-temperature periods. During the ecological restoration period, the median CH4 fluxes before, during, and after high-temperature events were 0.05–0.17, 0.07–0.25, and 0.04–0.15 μg·m?2·s?1, respectively, representing reductions of approximately 72%–95% compared to the aquaculture period (0.42–0.62, 1.05–5.26, and 0.71–4.60 μg·m?2·s?1, respectively). This study provides a theoretical basis for understanding the response mechanisms of carbon cycling in shallow lakes to climate warming and ecological management.