Abstract: Event volunteers play a crucial role in ensuring the operation of mega-sporting events. In this study, in-depth interviews were conducted on volunteers and managers at three mega-sporting events held in China in recent years to delve into the organizational socialization process and tactics of event volunteers. The findings reveal that the process of organizational socialization of event volunteers cover four phases: recruitment, training and selection, identity and responsibility clarification, and reflection. The organizational socialization tactics of mega-sporting event volunteers contain institutionalized tactics and individualized tactics. Institutionalized tactics include value transmission, mentoring, formal communication, and rewards and punishments; individualized tactics encompass informal communication, multiple identities, informal cooperation, minor transgressions, and conflict avoidance. Institutionalized tactics are primarily employed in the work-related tasks, whereas individualized tactics are mainly utilized for the maintenance of interpersonal relationships. During this process, institutional tactics play a fundamental role; as socialization progresses, the significance of individualized tactics becomes increasingly apparent.