Abstract: In order to elucidate the correlation between insect diversity and elevation gradient on the Qinghai-Tibetan Plateau, a study was conducted on the elevation gradient pattern of insect diversity in the Diqing Tibetan Autonomous Prefecture on the southeastern edge of the Tibetan Plateau, with an elevation range of 1600-3800 m above the sea level. Based on the alpha diversity index and Jaccard similarity index, the effect of elevation gradient on the distribution pattern of insect diversity was explored using regression analysis, principal component analysis and beta diversity decomposition. The results showed that the southeastern edge of the Tibetan Plateau had high insect diversity. 5141 insects belonging to 13 orders and 80 families were collected in four field surveys. The composition of insect communities varies along the elevation gradient, with a greater number of insect groups observed at lower elevations than at higher elevations. This may be attributed to more favorable thermal and hydrological conditions, as well as the heterogeneity of habitats at lower elevations, which may provide suitable habitats for different insect groups. The alpha diversity indices of insects decreased with increasing elevation. This phenomenon is likely attributable to the concomitant decrease in temperature and change in vegetation type associated with the elevation gradient. The Jaccard similarity index of insect communities at different elevation gradients ranged from 0.36 to 0.56, and most of these coefficients were in the moderately different or moderately similar range. The exception was in low elevation region, where the similarity of insect communities between adjacent elevation gradients gradually decreased with increasing elevation. This trend may be caused by the changes in environmental pressure due to the increase in elevation gradients. Furthermore, the differentiation of species adaptability to the specific elevation gradient is evident. The study demonstrates that the distribution pattern of insect diversity on the southeastern edge of the Tibetan Plateau is significantly affected by the elevation gradient, with higher insect diversity at lower elevations. Additionally, different elevation ranges have their own dominant insect taxa, and the diversity differences between elevation gradients are mainly due to turnover rather than nestedness. The findings of this study provide a significant scientific foundation for the conservation of insect diversity on the Qinghai-Tibetan Plateau.