Woody plant encroachment or shrub encroachment is a globally ecological environment problem, which has widely occurred on the Qinghai-Tibet Plateau in recent years. However, the temporal and spatial characteristics of woody plant expansion on the Tibetan Plateau and its impact on local land surface temperature (LST) are still unclear. This study uses MODIS land cover products to identify the spatial distribution of woody plant encroachment on the Qinghai-Tibet Plateau, and explores its impact on LST, albedo, and evapotranspiration during the growing season based on the moving-window searching method. The results depicted an overall increasing trend of the range and extent of woody plant encroachment from 2001 to 2018. In 2018, woody plant encroachment on the Qinghai-Tibet Plateau decreased daytime LST by (2.60±0.34)℃, and increased nighttime LST by (0.94±0.22)℃, while its net effect decreased the daily average LST by (0.83±0.24)℃ during the growing season. This is because the cooling effect including the increase of evapotranspiration ((+13.46±6.65)mm/a) exceeds the warming effect represented by the decrease of albedo (-0.031±0.003). Background climate strongly influences the results, that is, precipitation dominates the change of daytime LST, but temperature plays a more important role in that of nighttime LST. In general, there is a greater tendency for local LST of the sites with lower air temperature, larger precipitation rate and lower elevation to decrease. Contrary to the tendency for wetter sites to cool more in the same year, drier years had a stronger cooling effect on daytime LST among different hydrological years, which is possibly due to the differences between woody and herbaceous plants' ability to access water from deep soil. Understanding the potential of woody plant encroachment to change LST is beneficial for accurately predicting the future climate change on the Qinghai-Tibet Plateau and providing references for land use and management.