In recent years,the growing practice of "Party building drives trade union building"in private enterprise has become a hot issue,but few academic studies discuss it.Based on the case study of Guangdong Liby Group,the paper uses social exchange theory to explore "Party building drives trade union building"and the process mechanism of building harmonious labor relations in Liby Group.The rescarch shows that based on policy guidance,private enterprise can create a good atmosphere and an operating mode of "Party building drives trade union building,which is beneficial to building harmonious labor relations and has an impor- tant reference for private enterprises in China.