The lakes of the Tibetan Plateau are important indicators of climate change, and their expansion or contraction also has an important impact on the natural environment of the Tibetan Plateau. Three typical lakes (Qinghai Lake, Yangzhuoyong Lake, and Ulan Ula Lake) located in different climatic sub-zones of the Qinghai-Tibet Plateau were selected and remote sensing monitoring methods were used to study the temporal and spatial variation of the hydrological characteristics of the three typical lakes from 1985 to 2021, reveal the role of key climatic factors, and further explore the influence of glaciers and frozen soil on typical lakes. The results show that the area and water level of Qinghai Lake show a significant upward trend during the study period. The area increased by 238.68km2, the water level increased by 1.32m, and the space showed a trend of expansion in the east-west direction; the area of Yangzhuoyong Lake showed a trend of first fluctuating and then decreasing, decreasing by 16.316km2 and 3.25 meters respectively, and the overall spatial situation showed a shrinking trend from all sides to the center; the area and water level of Ulan Ula Lake showed a significant upward trend, increasing by 125.575km2 and 8.12 meters respectively, and the expansion area was mainly concentrated in the south. The analysis of key climatic factors showed that precipitation change was the key factor affecting the area change of Qinghai Lake and Yanghu Lake, and the area change and precipitation lagged. The main reason for the rise in the water level of Ulan Ula Lake is the seasonal thawing of the frozen soil caused by the increase in temperature. Exploring the changes of lake area on the Qinghai-Tibet Plateau is of great guiding significance for in-depth study of global climate change and surface water resources assessment.