Eutrophic lakes are one of the important sources of nitrous oxide (N2O) emission, accurate estimation of their N2O emissions is crucial for evaluating the global N2O budget. However, constrained by the spatiotemporal variability of N2O emissions and the complexity of influencing factors, the specific mechanisms by which eutrophication processes affect N2O emissions remain unclear. Therefore, this study selected Lake Taihu, the third largest freshwater lake in China, as the research area. The N2O diffusive fluxes at the water-air interface were measured using the headspace equilibrium method, and the key factors driving N2O emissions were analyzed. The results showed that: (1) The N2O diffusive fluxes at the water-air interface of Lake Taihu ranged from 1.7 to 30.6 μmol/m2/d, with an annual average of 8.9±5.1 μmol/m2/d. Although the eutrophication level in algal-dominated zones was significantly higher than that in macrophyte-dominated and transitional zones (P<0.05), no significant difference in N2O emissions was detected among the three zones (P>0.05). This finding indicates that for moderately eutrophic lakes like Lake Taihu, increasing the eutrophication does not necessarily lead to elevated in lake N2O emissions. (2) Water temperature was the most important factor affecting N2O emissions from Lake Taihu. Further analysis revealed that N2O emission processes in Lake Taihu were co-regulated by the concentrations of dissolved organic carbon and nitrate in the water column. (3) Based on these findings, this study developed a multiple regression model which can effectively correct the overestimation of N2O emissions from Lake Taihu by the IPCC simply through the inclusion of water temperature, an easily accessible environmental factor. This study broads our understanding of how lake eutrophication processes influence N2O emissions, while also providing scientific support for the estimation of N2O emissions.