<p>Permeability between vocational and higher education has become a global policy priority, yet its equity implications remain contested. While reforms aim to bridge educational sectors, whether permeability produces equitable mobility or stratified inclusion remains underexplored, particularly in non-Western contexts. This study tests whether permeability is “necessary but not sufficient” for educational equity through empirical analysis of China’s integration reforms (2010–2025). Using multi-level mixed methods, the study examines how permeability reforms expand vocational students’ higher education access and shape their social mobility pathways. Findings reveal systematic violations of three critical conditions for equitable permeability, including program quality alignment, institutional status parity, and labor market recognition. Vocational students show a lower cognitive preparation, institutions engage in mission drift undermining vocational identity, and graduates face small but significant wage penalties despite obtaining identical credentials. This produces “stratified mobility”, simultaneous access expansion and inequality reproduction through differentiated pathways. The pattern likely characterizes systems pursuing vocational-academic integration under massification pressures, offering design principles for equitable permeability applicable across national contexts.</p>