Based on the Enhanced Vegetation Index (EVI) and Net Primary Productivity (NPP) data of the Karst areas in Southwest China from 2000 to 2020, the socioeconomic factors such as population pressure, rural economy and non-farm economy were subdivided. A linear mixed model was used to quantitatively assess the relative contribution of each socio-economic factor to the EVI and NPP, and to explore the relationship between socio-economic development and vegetation restoration. The results showed that: (1) Vegetation in the Karst region of Southwest China presented an upward trend from 2000 to 2020. (2) Overall socio-economic factors contributed more to vegetation recovery than natural factors, and in this paper the contribution of socioeconomic factors to EVI was 26.6% and to NPP was 41%. (3) Among the socio-economic factors, the relative contribution of non-farm economic factors to vegetation restoration was the highest, with a contribution rate of 19.1% to EVI and 14.7% to NPP. (4) Among the subdivided socio-economic factors, the tertiary industry had the highest relative contribution to vegetation restoration, in which the relative contribution to EVI and NPP was 11.8% and 14.7%, respectively. In summary, except for ecological engineering, the influence of the remaining socioeconomic factors on vegetation restoration, although indirect or lagging, is equally important and cannot be ignored.