Nitrogen (N) and phosphorus (P) are essential nutrients that regulate terrestrial ecosystem productivity and shape the structure and function of soil microbial communities. Their continuous input not only directly affects the energy and nutrient balance of wetland ecosystems but also induce indirect effects through complex biogeochemical processes. As transitional zones between land and sea, coastal estuaries are highly sensitive to environmental changes and represent relatively fragile ecosystems while also serving as sinks for N and P from terrestrial and atmospheric sources. In recent years, human activities have intensified N and P loading, significantly increasing their bioavailability within these ecosystems. However, the specific mechanisms by which these changes affect soil enzyme activities and nutrient balance in coastal estuarine wetlands remain poorly understood. To address this knowledge gap, we conducted in-situ experiments in the Min River estuarine wetland, investigating the effects of exogenous N, P, and combined N+P additions on soil enzyme activities and enzyme stoichiometric characteristics. The results indicated that: ①Compared with the control treatment, N, P, and N+P treatments significantly enhanced the activities of β-1,4-glucosidase and cellobiose hydrolase in wetland soils (P<0.05), with the most pronounced effects observed under N addition, leading to increases of 313.66% and 78.38%, respectively. The activities of β-1,4-N-acetylaminoglucosidase and leucine aminopeptidase exhibited opposite responses under different treatments. β-1,4-N-acetylaminoglucosidase activity increased by 19.49% and 6.35% with N and P addition, respectively, but decreased by 8.27% under the N+P treatment. Conversely, leucine aminopeptidase activity decreased by 34.17% and 21.32% with N and P addition, respectively, but significantly increased by 66.87% under N+P treatment. Alkaline phosphatase activity exhibited minimal changes, increasing by 2.47% with N addition but decreasing by 18.3% and 4.66% with P and N+P addition, respectively, with none of these changes reaching statistical significance. Furthermore, N, P, and N+P treatments significantly increased the enzyme carbon-nitrogen ratio and enzyme carbon-phosphorus ratio (P<0.05), with the most substantial increase observed under N addition. ②Enzyme stoichiometry analysis indicated that microbial communities in the Min River estuarine wetland soils are co-limited by N and carbon (C). Although short-term N and P additions enhanced microbial nutrient responses, they did not completely alleviate N limitation. Instead, they exacerbated C limitation, suggesting a shift in microbial resource allocation under nutrient enrichment. ③Correlation and redundancy analyses demonstrated that exogenous N, P, and N+P inputs regulated soil enzyme activities and enzyme stoichiometry through key soil properties, including the soil C:N ratio, available P, microbial C, and organic matter. These findings deepen our understanding of nutrient cycling mechanisms in wetland ecosystems and provide critical insights for predicting wetland responses to environmental change. Additionally, they offer valuable guidance for developing effective conservation and management strategies aimed at maintaining the ecological functions of coastal wetlands.