The aim of this study was to clarify the effects of yak and Tibetan sheep trampling on the grassland in Qinghai-Tibetan Plateau. The effects of simulated trampling and rainfall on soil nutrients and enzyme activity in an alpine meadow were studied through two years of two-factor control experiments. The results showed that simulated trampling increased soil available nitrogen and available potassium but decreased soil total phosphorus and urease in the 0-20 cm soil layer, and decreased available phosphorus, alkaline phosphatase activity, and organic matter content in the 0-10 cm soil layer. Moderate trampling promoted the mineralization of soil total nitrogen. The soil nitrogen content in the 0-30 cm layer and total phosphorus content and urease activity in the 0-20 cm layer each showed a trend of a single peak curve with increased rainfall, reaching its peak at the average level of rainfall. Precipitation significantly reduced available nitrogen, available phosphorus, and available potassium in the 0-30 cm soil layer and total potassium in the 0-10 cm soil layer, but had no significant effect on soil organic matter content (P > 0.05). Under the same grazing intensity, the soil nutrients and enzyme activity of soil with Tibetan sheep were better than those with yak, but the difference was not significant (P > 0.05). Overall, livestock trampling promoted the mineralization of soil nitrogen and potassium, inhibited the accumulation of phosphorus, and accelerated the depletion of soil organic matter in the topsoil, while reducing soil urease and alkaline phosphatase activities. Moderate rainfall increased total nitrogen and total phosphorus contents and enzyme activity, while excessive rainfall had the opposite effect. Soil nutrient cycling and enzyme activity under the coupling of moderate trampling and precipitation were better than those of severe trampling and no trampling. As part of appropriate grazing and utilization of grassland, the influences of soil moisture and livestock species should be taken seriously. When grassland is under drought or soil water content is too high, the proportion of yak in grazing livestock should be reduced to increase the proportion of Tibetan sheep, so as to make the grassland achieve healthy and sustainable development.