This study explores the internal logic and influence mechanism of government-provided vocational skills training (GPVST) and migrant workers’ income level (IL) and income satisfaction (IS) using propensity score matching with difference-in-differences (PSM–DID), and it utilizes panel data collected by China Labor-force Dynamic Survey (CLDS) in 2016 and 2018. The study indicates that participation in GPVST positively affects the IL and IS of migrant workers; further analysis reveals that GPVST is more capable of raising the foreign migrant workers’ IL, and that the positive effect on the IS pertaining to the older generation of migrant workers and local migrant workers is more significant. Mechanism analysis reveals that GPVST can indirectly enhance the IL and IS of migrant workers by increasing the skill-enhancing effect exerted by human capital, information-interaction effect exerted by social capital, and trickle-down effect exerted by financial capital; however, generally, the indirect effect of livelihood capital is stronger in the impact of GPVST on the IL, whereas the direct effect is stronger in the impact of GPVST on IS. The findings herein exhibit crucial practical value for strengthening GPVST and enhancing the livelihood capital and income of migrant workers.