The Yellow River Basin has an important strategic position and is an important ecological barrier in China. Quantitative assessment of the impact of climate change and human activities on vegetation change in the Yellow River Basin is of great significance to government management and decision-making. Taking the Yellow River Basin as the research area, the temporal and spatial dynamic changes of normalized difference vegetation index (NDVI) from 1982 to 2019 were analyzed, the contributions of climate change and human activities on NDVI were quantitatively calculated, and the influencing factors of NDVI were mapped. On this basis, the impact of ecological construction project on vegetation change was discussed, and its effectiveness was evaluated. The results showed that: (1) From 1982 to 2019, the NDVI of the Yellow River Basin showed a significant increasing trend, with a change trend of 0.002 4/a. The regions with significant degradation in NDVI were distributed in the west and south of the basin, and the regions with significant increase in NDVI were distributed in the middle and north of the basin. (2) Vegetation change in the Yellow River Basin was the result of the joint action of climate factors and human activities. The contribution of climate factors to NDVI change was 82.74%, and the contribution of human activities was 17.62%. Climate factors were the dominant factors of vegetation change in the Yellow River Basin, but the influence of human activities in vegetation change was gradually increasing. (3) The vegetation restoration of the three ecological construction projects followed the order of the Three-North Shelter Forest Program>Shelter Forest Belt Project in Middle Reach of the Huanghe River>Afforestation of Taihang Mountain, and the ecological construction project played a significant role in promoting vegetation restoration.