The absorption, transformation and content of nitrogen in soil are the key factors affecting the growth of vegetation. In order to explore the effects of various degradation conditions of wetland vegetation on the content of soil nitrogen components and related enzyme activities, as well as their relationship, research was conducted in sample areas with the following vegetation conditions (non-degraded CK, slightly degraded SD, moderately degraded MD and severely degraded HD) in Gahai wetland, Gannan.We combined field sampling and laboratory experiments, and analysed the variation characteristics of the content of various nitrogen components (total nitrogen, ammonium nitrogen, nitrate nitrogen and microbial biomass nitrogen) under different vegetation conditions, as well as the correlation between soil nitrogen invertase activities (protease, urease, nitrate reductase and nitrite reductase). The results show that: (1) Under the condition of vegetation degradation, the soil moisture content decreased gradually, and the soil temperature first decreased and then increased with the aggravation of the degree of degradation; (2) With the aggravation of vegetation degradation, the content of soil nitrate nitrogen showed an increasing trend, while the contents of total nitrogen, ammonium nitrogen and microbial biomass nitrogen showed a decreasing trend. Soil protease activity decreased with the degree of degradation, and the unease activity first decreased and then increased; the activity of heavily degraded was the highest, and the activity of slightly degraded was the lowest. The nitrate reductase activity increased with the aggravation of the degree of degradation, and the nitrite reductase activity showed a trend of "up-down-up", that is, the slightly degraded activity was the highest, while that of the non-degraded and moderately degraded was lower; (3) Soil protease activity has a very significant positive correlation with total nitrogen, ammonium nitrogen and microbial nitrogen content (P < 0.01), and a significant negative correlation with nitrate nitrogen content (P < 0.05). The activity of nitrate reductase was opposite to that of protease, and has a significant negative correlation with total nitrogen, ammonium nitrogen and microbial nitrogen. Urease activity has a very significant positive correlation with microbial nitrogen content (P < 0.01) and a significant positive correlation with total nitrogen content (P < 0.05). Nitrite reductase activity has a very significant positive correlation with total nitrogen and ammonium nitrogen content (P < 0.01), and a significant negative correlation with nitrate nitrogen content (P < 0.05). In summary, under the various degraded conditions of vegetation in Gahai wetland, the increase in soil nitrogen content can effectively increase the activity of related enzymes.