Under high-standard opening-up, foreign shareholders have become an important channel through which firms access global resources. Using A-share listed firms from 2011 to 2024, this paper finds that equity internationalization significantly promotes firms’ human capital structure upgrading through market expansion, technological advancement, and supervisory governance； CEO overseas experience and a favorable business environment strengthen this effect. This paper provides important implications for improving high-standard opening-up policies and optimizing firms’ human capital structure.