Net Primary Productivity (NPP) of vegetation has been widely used to directly reflect the carbon sequestration capacity and environmental changes of terrestrial ecosystems. However, research on the impact of human activities across terrains on vegetation NPP changes in the Qinba Mountains is still insufficient. Based on the CASA model, the long-term spatial distribution of NPP in the Qinba Mountains from 2001 to 2022 and its topographic effects were comprehensively analyzed using linear trend analysis, transition matrix, and residual analysis. Furthermore, the relative contribution rates of climate change and human activities to NPP changes were explored. The main findings are as follows: ①The spatial distribution of NPP in the Qinba Mountains exhibited a pattern of the middle height around the bottom, with a mean of 585.11g C/m², and an annual increase rate of 4.30g C/m² from 2001 to 2022. ②The highest annual mean NPP was found in forestland among land use types. The highest increasing rate of NPP (8.17g C m^-2 a^-1) was found in the area of conversion of farmland to forest, indicating an effective land transfer type for NPP growth in the Qinba Mountains; ③The NPP varies significantly with altitude and slope. The vegetation NPP increased with increasing elevation below 3400 m and decreased significantly above it. The annual mean and trend of vegetation NPP are relatively high within the slope range of 10-40°; ④The change in NPP in the Qinba Mountains was driven by the combined impact from climate change and human activities, with the relative contribution rates of 37.81% and 62.19%, respectively. Human activities significantly increased the vegetation NPP especially in ecologically fragile areas such as Longnan region.