<p>This study examined how parent-child communication is associated with emotion regulation in left-behind children, with a focus on the mediating roles of beneficial explanation and parent-child attachment. Surveys were administered to 1186 left-behind children, including the Parent-Child Communication Questionnaire, Beneficial Explanation Questionnaire, Parent-Child Attachment Questionnaire, and Emotion Regulation Questionnaire. The results indicated that beneficial explanation and parent-child attachment served as mediating variables in the association between parent-child communication and emotion regulation, specifically in the dimension of cognitive reappraisal. Three specific mediation pathways were identified: the independent mediating role of beneficial explanation, the independent mediating role of parent-child attachment, and the chain mediating role of beneficial explanation and parent-child attachment. However, the chain mediation involving beneficial explanation and parent-child attachment did not significantly predict the relationship between parent-child communication and emotion regulation in terms of expressive suppression. In conclusion, parent-child communication was found to predict cognitive reappraisal only through the mediating effects of beneficial explanation and parent-child attachment. Overall, parent-child communication could only predict positive emotion regulation through beneficial explanation and parent-child attachment. This study provides valuable insights into the complex mechanisms linking parent-child communication and emotion regulation among left-behind children.</p>