The standardized precipitation index SPI and remote sensing vegetation index (NDVI, EVI) were used to quantify the evolution characteristics of growing season vegetation and hydrological drought in the Three River Source Region (TRSR) from 1961 to 2018. The spatio-temporal evolution trends of drought and vegetation in the Three River Source Region from 1961 to 2018 were analyzed based on the Mann-Kendall trend test. In addition, the spatio-temporal evolution trend of vegetation, and the correlation between different drought variables and vegetation index was analyzed based on the Spearman's level correlation coefficient. The results show that the seasonal drought events in the study area occurred in 1963, 1966, 1984, 1992, 2000 and 2017, there was significant humidification in spring (mean trend characteristic value Z=2.28), and both the source of Lancang River and the middle of the source of Yangtze River in autumn faced a non-significant drought threat. In May, there was a significant increase of vegetation in northern of the Yellow River source, while there was an insignificant trend of vegetation degradation in the middle of Yangtze River source and Lancang River source in September. The variation trend of vegetation is that the north is stronger than the south and the west is stronger than the east from 2000 to 2018. Since the 21st century, drought events have a certain response relationship with vegetation, and SPI3 has a significant positive correlation with the vegetation index.