Reuse after short-term grazing exclusion (RSTG) is widely used to restore the degraded grassland in ecological engineering. It's vital to understand the effects of RSTG on grassland restoration for optimal adjustment of subsequent projects. There is a growing number of research literature in the effects of grazing exclusion and grazing, while little attention has been devoted to the long-term effects of RSTG on grassland. This study took the grazing exclusion plots of Beijing-Tianjin Sand Source Control Project (2002-2005) in Xilingol as study objects. Based on paired sampling survey and remote sensing data analysis, we studied the variation of grassland plant community in a period of 20 years, including grazing exclusion period and grassland reuse period. Results showed that the height, coverage and aboveground biomass of grassland increased rapidly during 3-year grazing exclusion period, while these indicators, which remained significantly higher than those in continuous grazing plots, decreased slightly and reached a steak state after grassland reuse. There was a non-significantly increasing trend of fractional vegetation cover (FVC) and a significantly increasing trend of net primary productivity (NPP) in RSTG plots during 2002-2020, and the proportion of plots with increasing FVC and NPP decreased in order of temperate meadow, temperate desert steppe and temperate steppe. Generally, reuse after 3-year grazing exclusion could be beneficial to restore grassland community.