Parenting practices and relationships with peers are crucial aspects of youth socialization. Although theoretically expected reciprocal associations between changes in maladaptive parenting and adolescent peer victimization exist, there is a lack of studies that examine this link and address the mediating mechanisms at the within-person level. This longitudinal study examined reciprocal relations between peer victimization and two types of maladaptive parenting including harsh punishment and psychological control, and the potential mediating roles of internalizing and externalizing problems within these relations, by disentangling between- and within-person effects. A total of 4,731 Chinese early adolescents (44.9% girls; Mage = 10.91 years, SD = 0.72) participated in a four-wave longitudinal study with 6-month intervals. The results of random intercept cross-lagged panel modeling showed: (a) harsh punishment did not directly predict peer victimization, and vice versa; (b) psychological control directly predicted peer victimization, and vice versa; (c) psychological control indirectly predicted peer victimization via internalizing problems, and peer victimization also indirectly predicted psychological control via internalizing problems. These findings provide evidence of a bidirectional spillover effect between psychological control and peer victimization at the within-person level, suggesting Chinese early adolescents may become caught in a vicious cycle directly or indirectly via their internalizing problems.