Soil moisture is one of the key factors affecting the ecological processes and ecological carrying capacity of alpine meadows in the Qinghai-Tibet Plateau. Mastering its change characteristics is of great significance for ecological protection and restoration in alpine region. Based on the soil moisture data monitored by hobo soil temperature and humidity instrument (HOBO Data Loggers-Onset Corporation of USA), soil moisture change characteristics during August 2019 and August 2020 of three layers L1 (0—5 cm), L2 (5—15 cm) and L3 (15—30 cm) of alpine meadow topsoil under different degradation stage sites, which were non-degradation (ND), light to moderate degradation (LMD), highly degradation (HD), in the Three-River Source Region were analyzed. The results showed that: (1) There were significant seasonal variations in soil water content under different degradation stages. The high values mainly distributed in summer, while the low values distributed in winter and spring. The intra-annual mean values of topsoil water content under different degradation types followed the order of LMD (0.320 cm³/cm³)> ND (0.284 cm³/cm³) >HD (0.211 cm³/cm³). (2) After continuous rainfall in summer, the soil water content began to decrease significantly after 24 hours. Among them, the change range of L1 layer was the largest and that of L3 layer was the smallest. (3) The soil depth of 0—5 cm in ND and LMD alpine meadows, and the 5—15 cm of HD alpine meadows corresponded to a higher water content layer, because that the soil water content was significantly negatively correlated to soil water content and soil capacity, and significantly positively correlated to C/N and organic carbon.