Objective. WeChat-based extended care has been widely applied in clinical practice such as preoperative assistance in children with congenital heart disease and children with ventricular septal defect. In this study, we aimed to explore the impacts of WeChat-based extended care on the growth and development of preterm infants (PIs) and the nursing satisfaction of their family members. Methods. From June 2019 to August 2021, 85 PIs and their mothers were selected as the research participants. Among them, 46 pairs receiving WeChat-based extended care were served as the WeChat group, and 39 pairs receiving routine extended care were taken as the control group. After 6 months of intervention, the two groups of PIs were compared in terms of physical development, IQ, and neurological and gastrointestinal functions. For mothers, their psychological states were assessed after intervention using the self-rating anxiety/depression scale (SAS/SDS), and the nursing satisfaction was counted. Results. After nursing intervention, better physical and IQ development of PIs were observed in the WeChat group compared with the control group ( P < 0.05 ). The WeChat group also had notably reduced level of neuron-specific enolase (NSE) and s100β protein related to nerve function than that in the control group and exhibited significant higher levels of serum gastrin (GAS) and motilin (MTL) associated with gastrointestinal function ( P < 0.05 ). Besides, the WeChat group presented lower SAS and SDS scores and higher nursing satisfaction than the control group in delivery women ( P < 0.05 ). Conclusion. WeChat-based extended care can effectively improve the growth and development and various physical functions of PIs. At the same time, it is helpful to improve maternal psychological states and nursing satisfaction of delivery women, which is worth of clinical application.