This research calculated vegetation coverage on the Loess Plateau from 2000 to 2020 by using the MODIS-NDVI vegetation index, analyzed its relationship with rainfall, temperature, slope and soil by using the transfer matrix and other methods. The results showed that:(1) The vegetation coverage increased from 0.39 to 0.61, and increased rapidly after 2017. (2) The area ratio of significantly improved and extremely significantly improved reached 37.93%. The coverage was dominated by low and middle-low before 2009, and dominated by medium and higher coverage after 2010. The proportion of middle-high coverage was the highest after 2019. (3) The conversion ratios of low, medium-low, medium and medium-high cover to the higher cover were 93.10%, 96.57%, 82.99%, 43.34% respectively. The conversion ratios of medium-low, medium, medium-high and high cover to the lower cover were 0.30%, 2.21%, 7.83%, 12.47% respectively. (4) The changes of vegetation coverage were sensitive to the changes of temperature and rainfall. The vegetation coverages of slope, steep slope and leached soil were higher. Human interventions, such as policies and soil conservation measures, played an important role in vegetation coverage improvement.