Research on laboratory animals is an important issue in biomedicine. Children are a special drug-using population. The selection of suitable experimental animals is a key issue to ensure the scientific quality of research for pediatric drugs. Based on the review of a large number of literature, the authors summarized the application of suckling mice in the pharmacological research and toxicological evaluation of pediatric drugs for the treatment of common diseases in children. We also summarized the existing problems in pediatric toxicology and proposed solutions for providing a reference of test animal application in pediatric drug research.