Studies have shown that childhood maltreatment can negatively predict psychosocial flourishing among emerging adults. However, few studies have revealed the factors that can protect the psychosocial flourishing of emerging adults who experienced maltreatment during childhood. Based on theoretical and empirical considerations, this study investigated whether and how psychological suzhi (a positive quality that can facilitate individuals’ adaptation to environment) plays a protective role in the relationship between childhood maltreatment and psychosocial flourishing among emerging adults. A total of 2863 Chinese emerging adults (M_age = 19.96 years) completed the self-report measures of the Childhood Trauma Questionnaire, Psychological Suzhi Questionnaire, Rosenberg Self-esteem Scale, and Flourishing Scale. The moderated analyses showed that childhood maltreatment had a less negative impact on psychological flourishing in high psychological suzhi emerging adults than in low psychological suzhi emerging adults. Part of the moderating effect of psychological suzhi is mediated through self-esteem. These results demonstrated that psychological suzhi plays a buffering effect between childhood maltreatment and psychosocial flourishing, and part of the effect is achieved by mediated variable self-esteem. These findings are discussed, and practical implications are presented.