The issue of excessive mobile phone use among mothers currently is growing increasingly significant due to the rapid growth of smartphones and other technological items. Given that women are the primary caregivers for preschool-aged children, it is imperative to thoroughly investigate the detrimental impacts of mothers' problematic mobile phone use on the hyperactive behaviors of their children, as well as the underlying mechanisms. In this study, 924 Chinese mothers and their children are surveyed. The study looks into the moderating effects of parenting support in this context as well as the chain mediating roles of mothers' parent-child interaction disorder and work-family conflict in the effects of mothers' problematic cell phone use on preschoolers' hyperactive behaviors. Analysis is conducted on the moderating impact of parental support in this as well. The results find that boys have significantly higher levels of hyperactive behavior than girls; maternal problematic cell phone use significantly positively predicts preschoolers' hyperactive behavior; maternal problematic cell phone use could indirectly affect preschoolers' hyperactive behavior through the chain-mediated effects of work-family conflict and parent-child interaction disorder, and parenting support moderates the predictive effects of parent-child interaction disorder on preschoolers' hyperactive behavior. This study reveals potential ways in which mothers' problematic mobile phone use affects preschoolers' hyperactivity behaviors in the Chinese context. The findings provide a multidimensional (protective and risk factors) indication of how to reduce the impact of mothers' problematic mobile phone use on preschoolers' levels of hyperactivity behaviors, which would contribute to improving children's mental health. However, this is a cross-sectional study and other factors may also play an important role in this pathway.