<p>Parent–child relationship quality is important for effective family functioning and children’s healthy development; and understanding its influencing factors, improvement pathways, and underlying mechanisms has valuable theoretical and practical implications. Grounded in the model of mindful parenting, this study explored the actor and partner effects of parental mindful parenting on parent-child relationship quality, as well as the mediating effects of parenting self-efficacy, within a dyadic context. Dyadic data were collected from 979 dyads of heterosexual parents (Mothers, <i>M</i>_<i>age</i> = 38.127, <i>SD</i>_<i>age</i> = 5.047; Fathers, <i>M</i>_<i>age</i> = 40.707, <i>SD</i>_<i>age</i> = 5.957). The results of the Actor-Partner Interdependence Model showed that both maternal and paternal mindful parenting had significant actor and partner effects on parent-child relationship quality, with no significant differences between mothers and fathers. Furthermore, the results of the Actor-Partner Interdependence Mediation Model revealed that maternal parenting self-efficacy significantly mediated both effects of maternal mindful parenting on mother-child and father-child relationship qualities, while paternal parenting self-efficacy significantly mediated both effects of paternal mindful parenting on father-child and mother-child relationship qualities. These findings validate the model of mindful parenting from a dyadic perspective, and deepen the understanding of parent–child relationship quality, providing valuable references and practical insights for improving parent-child relationship.</p>