Over the years, the ecological restoration measures implemented in Lvliang contiguous poverty area have had a great impact on its ecological environment. In order to grasp the change of net primary productivity of vegetation in this area since the implementation of ecological restoration measures (2000), this study used the remote sensing data of 2000-2018 and the CASA model based on the utilization rate of light energy to simulate it, and analyzed the main control factors leading to its change. The results showed that:(1) net primary productivity (NPP) in Lvliang contiguous poverty area increased as a whole since 2000, of which 93.46% of the regional NPP increased, 6.54% of the regional NPP decreased, and the regional NPP decreased from 2010 to 2015. (2) Affected by human activities, in the past 18 years, the regional land use type changed significantly, the cultivated land area decreased, the grassland area remained basically stable, the woodland and urban area increased, and the urban area expanded rapidly. The NPP characteristics under different land use types were significantly different. The annually average NPP of the cultivated land increased most rapidly, which was 5.9 gC m^-2 a^-1, and the forest land was the most stable, which was 1.32 gC m^-2 a^-1. (3) The fluctuation of precipitation in the study area had a significant impact on the change of regional NPP. The change of precipitation in the future climate change may have direct impact on regional NPP. The results will provide importantly theoretical support for regional ecological restoration, targeted poverty alleviation and economic development in the middle reaches of the Yellow River.