Abstract: Social network analysis was used to verify the moderating effect between the exerciser schema and the health promotion lifestyle of adolescents on the "online exercise friendship" network structure (including internet scale, density, hierarchy and constraint). The results showed that: ① The main effect test showed that adolescent exerciser schema positively influenced exerciser's health promotion lifestyles. The "online exercise friendship" network hierarchy and network constraints negatively influenced the dependent variables, indicating that the network structure was flat, that the "power" and "influence" of small groups were decentered, and the network constraints were low, with many structural holes, which was an excellent prediction for the dependent variables. ② In the interaction effect test of exerciser schema, network density positively affected the dependent variables and network constraint negatively affected the dependent variables. That is, when the level of exerciser schema was the same, a high network density or a low network constraint had a more significant effect on health promotion lifestyles. ③ Network closure represented by network density and network constraint represented by structural holes coexisted and complemented each other, affecting the dependent variable in contradiction and unity. The results of significant network structure moderation effects provide empirical data and a possible theoretical basis for social mobilization strategies for sport and health in online small groups.