China's need for skilled workers to upgrade its industrial system is increasingly urgent due to global economic competition. Despite massive expansion of its Vocational Education and Training system over the past two decades, a significant skilled labour deficit remains. Current debates on the inefficacy of vocational education focuses on the lack of institutional synergies between education and industry but often overlooks the inherent conflicts within the vocational education system and micro-level skill formation processes. Our ethnographic research in two upper-secondary vocational schools unveils a disturbing trend: the rapid massification of vocational education, which prioritizes student enrolment numbers over educational quality, fails to address the demand for skill formation and skilled labour. It inadvertently generates adverse consequences for both administrative management and classroom instruction. Skill development frequently falls to after-school professional associations and an exclusive group of elite students. Meanwhile, reform initiatives, such as the craftsmanship campaign and skill competitions, benefit only a few without improving the employment prospects for the wider student population. These findings call for greater attention to the inherent tensions within China's Vocational Education and Training system. Only when there is a deeper understanding of the underlying causes of ineffective skill formation in vocational schools can China achieve its national goal of industrial upgrades.