Increasing the income of low-income groups and expanding the middle-income population to form an“olive-shaped” income distribution structure is an inevitable requirement for achieving common prosperity.Based on balanced panel data from 1706 counties across China，this study employs a two-way fixed effects model to examine the impact of industrial structure transformation at the county level on“raising the low and expanding the middle”among farmers.The study finds that the transformation of industrial structure in China’s counties generally exhibits a positive developmental trend，mainly reflected in the rationalization and upgrading of the industrial structure.Rationalization within county-level industrial structure transformation promotes the rational allocation of resources and enhances the alignment between farmers and non-agricultural employment opportunities，thereby facilitating the goals of“raising the low and expanding the middle”.In contrast，industrial structure upgrading demonstrates both driving effects and crowding-out effects.Moreover，heterogeneity analysis shows that the income-enhancing effect of industrial structure transformation is more pronounced in“growth-pole” counties compared to“stable-tier” counties，and the influence of rationalization and upgrading varies across different geographical locations.From a long-term perspective，industrial structure transformation at the county level can improve the income quality of low-income farmers，accelerate their entry into the middle-income group，effectively narrow the urban-rural income gap，and expedite the realization of an“olive-shaped” society.Based on these findings， policy implications include developing characteristic industries to enrich the people and enhancing the inclusiveness of non-agricultural employment.