Abstract: Refractive errors, including hyperopia, myopia and astigmatism, are common vision problems among children and adolescents in many countries and regions of the world, which seriously affect their health and quality of life. Preschool age is the key period to prevent vision problems among children. This study analyzes the factors associated with preschool children's ametropia and provides scientific evidence for the development of prevention and treatment strategies through a systematic literature review of the prevalence and factors associated with preschool children's ametropia in China and abroad.