With the development of volunteer service in China, the participants of volunteer service are getting younger and younger, and the motivation of participants is becoming more and more complicated. In this study, exploratory factor analysis and confirmatory factor analysis were carried out on the model by designing the constitutive model and combining with the survey on the service participation of 1530 young volunteers from 18 districts and counties in Chongqing, and the fitting degree was tested by using the high-order structural equation model. The results show that the youth volunteer participation motivation of Growth-improvement motivation, Fashion-herd motivation, Value-achievement motivation and Social-career motivations, Material -reality motivation are eliminated by the reliability test, and Growth-improvement motivation as strong factor-became the main motivation of youth participation in volunteer service. At the same time, the study found that the participation motivation of young volunteers also has certain differences in personal factors, cultural factors and economic factors. Based on the above research, the corresponding countermeasures are put forward to improve the motivation of young volunteers to participate in service.