The Qinghai-Tibetan Plateau, the third polar of Earth, responds sensitively to global climate change. Soil nematodes are important indicators of the structure and function of soil food web. However, few studies have been conducted on the effects of altered precipitation on the taxonomic composition and diversity of soil nematode community in alpine meadows on the Qinghai-Tibetan Plateau. Therefore, understanding of the impacts of climate change on the structure and function of the soil food web in alpine meadows was inadequate at present. To explore the effects of altered precipitation on soil nematode communities in alpine meadows, the precipitation experiment, including three reduction precipitation treatments (-90%, -50%, and -30%), a control treatment (CK, natural precipitation), and an addition precipitation treatment (+50%), was set up in an alpine meadow in northwest Sichuan in December 2015. The annual precipitations of the five treatments were 88 mm, 442 mm, 618 mm, 883 mm, and 1325 mm, respectively. The soil nematode communities and the environmental factors of plant and soil were investigated from the plots of the five precipitation treatments in September 2020. Soil nematodes were extracted from 50 g of fresh soil using Baermann funnels, and the changes in the taxonomic composition structure, abundance, diversity index, and ecological index were analyzed. The results showed that:(1) the taxonomic composition and abundance of the soil nematode communities changed significantly with the increased annual precipitation and no significant changes in the diversity index. The relative abundances decreased significantly for fungivores and increased significantly for plant parasites with the increased annual precipitation. (2) The abundances of soil nematode community and four trophic groups decreased significantly when the annual precipitation was less than 442 mm. The abundances decreased significantly for fungivores and increased significantly for plant parasites when the annual precipitation was more than 442 mm, resulting into the dominating trophic groups shifted from the bacterivores and fungivores to the bacterivores and plant parasites. (3) When the annual precipitation was more than 883 mm, the abundance of soil nematode community varied with no significance, but the channel index of the top 10 cm soil layer was smaller than 50, indicating that the function of bacterial decomposition pathway for the soil organic matter was strengthened, which was unfavorable to the accumulation of soil carbon and nutrients. (4) The changes in the contents of soil moisture and total nitrogen and pH induced by the altered annual precipitation were the determining drivers for the soil nematode communities. The results suggest that the abundance and diversity of soil nematode community in alpine meadows will be affected weakly, but the structure and function of soil food web will be affected strongly when the climate becomes more humid on the eastern edge of Qinghai-Tibetan Plateau in the future.