Youth employment has always been an important issue of concern to all sectors. A great deal of research has been conducted on the "wage premium" effect of trade unions, whilst little attention has been paid to whether trade unions can improve the wage income of young migrants. This study, based on micro data from China Migrants Dynamic Survey (CMDS) in 2017, empirically examines the "wage premium" effect of trade unions on young migrants. The study fi nds that joining the trade unions can signifi cantly increase the wage income of young migrants; but the "wage premium" effect of trade unions on young migrants is heterogeneous, with a greater improvement in wage income for females, cross-city migrants, especially ones of shorter duration of migration, those engaged in commercial and life service industries, and those working in foreign and joint ventures, state-owned enterprises, and the eastern regions. Moreover, joining the trade unions can also promote the signing of labor contracts between young migrants and enterprises, thereby increasing their wage income. It is also suggested in this study that in the future the grassroots organizations of trade unions should continue to be strengthened to protect the rights and interests of young migrants.