Nitrogen mineralization is one of the important links in ecosystem cycle, which affects ecosystem functions and nitrogen biogeochemical cycle. Therefore, it is important to study the evolution characteristics of soil nitrogen mineralization during the process of alpine wetland degradation, which help us to reveal the process of wetland soil nitrogen cycle in the context of climate change and other human disturbances. Four different wetland degradation gradients (non-degraded, slightly degraded, moderately degraded, and severely degraded) in the Gahai wetland areas were selected as the research objects. Using the in-situ resin core method, the temporal and spatial change characteristics of soil nitrogen mineralization and its relationship with soil environmental factors and enzyme activities were analyzed through the observation of soil nitrogen mineralization at different growth stages (early growth stage, peak growth stage, and wilting stage) in the plant growing season. The results show that the wetland degradation had a significant inhibitory effect on soil nitrogen mineralization. Among them, compared with non-degraded soil (0.143 mg kg^-1 d^-1), the mineralization rate of net nitrogen in slightly degraded, mildly degraded, and severely degraded, the values increased by 0.018, 0.025, 0.020 mg kg^-1 d^-1, respectively; with the intensification of degradation, the soil net ammoniation rates decreased gradually or remained unchange, while soil net nitrification rate increased. As time went by, the soil net nitrogen mineralization rates changed significantly for four degradation gradients. Except for the non-degraded stage, which had a maximum value in August, the maximum values of other degradation stages appeared in July (ranged from 0.217 to 0.305 mg kg^-1 d^-1). Compared with September and October, the value in August decreased by 0.137-0.217 mg kg^-1 d^-1 and 0.173-0.241 mg kg^-1 d^-1, respectively. Repeated-measures two-way ANOVA showed that Wetland degradation and culture time had a significant interaction effect on soil nitrogen mineralization (P<0.05); Redundancy analysis showed that the net nitrification rate was positively correlated with nitrate reductase, urease activity and temperature (P<0.05), but was negatively correlated with protease, nitrite reductase, and water content (P<0.05). However, the net ammoniation rate and net nitrogen mineralization rate were opposite. Soil water content contributed as much as 67.7% to the rate of soil net ammonia, nitrification and nitrogen mineralization, which was the main affecting factor driving the change of soil nitrogen mineralization during the degradation process of Gahai wetland. The research results provide a basis data for the development of mechanism models of nitrogen mineralization process in alpine wetlands under the background of climate change.