Abstract: Based on the data of MODIS16, ET, PET and CLCD remote sensing products in Sichuan Province from 2001 to 2020, combined with water deficit index, coefficient of variation, trend analysis method and Mann-Kendall trend test, the spatio-temporal variation characteristics of ET, PET and CWSI was deeply explored in Sichuan Province. The changes of ET, PET and CWSI were analyzed based on different land use types. The results showed that ET showed no significant increase trend from 2001 to 2020, with an average annual increase of 6.7739 mm. The overall trend of PET generally showed an insignificant decrease trend, with an annual decrease of 5.1192 mm. The overall CWSI showed a significant decrease trend, with an average annual decrease of 0.0045. The average annual ET in Sichuan Province was from 0 to 1390 mm, most of the western plateau areas were high-value areas, while most of the Sichuan basin areas were low-value aeas. The variation trend was between −4 and 4.29 mm·a⁻¹, showing a significant increase trend and low or low volatility. PET value was between 0 and 2550 mm, except for a few areas in central Sichuan Province, which are low-value, other areas are high-value. The variation trend was between −15.14 and 17.95 mm, and the overall trend was insignificant decreasing trend and low or high volatility. The CWSI value ranged from 0.066 to 0.917, with high values in the eastern and western parts of Sichuan Province and low values in the central part of Sichuan Province. The variation trend was between −0.0366 and 0.0208, showing a significant decreasing trend and low volatility.