Social distancing restrictions for COVID-19 epidemic prevention have substantially changed the field of youths’ social activities. Many studies have focused on the impact of epidemic-preventative social distancing on individual physical and mental health. However, in the field of social distancing for epidemic prevention, what are the changes in youth anti-epidemic action and states caused by their interpersonal resources and interactions? Responding to this question by studying the impact of the elements of social capital in youths’ anti-epidemic actions and anti-epidemic states could help identify an effective mechanism for balancing social distancing for effective epidemic prevention and sustainable social-participation development among youth. Bourdieu’s field theory holds that the elements of social capital change with a change in the field. Therefore, we introduced the specific elements of social capital as independent variables and used a multinomal logistic model to analyze and predict the levels of youth anti-epidemic action through an empirical investigation of 1043 young people in Guangdong Province, China. The results show that, first, level of social distancing for epidemic prevention shows differences by occupation status and income level and correlates with social support. Second, social support and social norms play positive roles in promoting youth participation in anti-epidemic activities when social distance is certain. Third, social capital has a significant positive effect on youth social satisfaction and core relationships; however, social trust has a significant negative effect on youth physical and mental health. This study emphasized that social distancing for epidemic prevention is a special social situational state, which is a field where social capital has an impact on the differential changes in the public-participating actions and habitus of youth.