The carbon cycling process in eutrophic water bodies has always been a prominent and critical concern in global aquatic ecosystems. This study conducted a year-long in-situ investigation of methane (CH₄) flux at the water-air interface in the campus landscape pond (Lianxin Pond) of China Three Gorges University. This study aims to assess the influence of eutrophication on CH₄ emissions. The findings revealed a CH₄ emission flux rate of 5.06 mg/(m²·h) at the water-air interface, contributing to atmospheric CH₄ levels. The CH₄ flux was influenced by temperature, wind speed, and chlorophyll-a, while showed significant temporal heterogeneity with the following order: summer (8.70 mg/(m²·h))＞winter (4.80 mg/(m²·h))＞spring (3.88 mg/(m²·h))＞autumn (2.87 mg/(m²·h)). Furthermore, the dominant pathway was identified as bubbling (the proportion of bubbling is 88.56%), during the day (0.11 mg/(m²·h)) slightly higher than the night (0.09 mg/(m²·h)). The difference of CH₄ emission flux in different seasons and day and night is related to the change of environmental factors such as temperature, wind speed and chlorophyll-a. With the increase of water eutrophication level, the CH₄ emission flux showed a non-linear increase trend. With the increase of eutrophication level, the release flux of CH₄ release flux showed nonlinear increase. Notably, the mean CH₄ flux in hyper-eutrophic water was 2 times greater than that in moderately eutrophic water. Controlling eutrophication is critical to reducing CH₄ emissions from water bodies, and can serve as a reference for reducing greenhouse gas emissions in other similar aquatic ecosystems.