Myopia has become a common eye disease in China and around the world. The myopia rate among children and adolescents in China has been continuously increasing, and it shows the characteristics of younger age and higher severity, seriously threatening eye health. According to recent studies, myopia is closely related to the axial length. During the progression of myopia, the excessively long axial length would lead to changes in ocular structure like the sclera, retina, and choroid, etc., thereby increasing the onset risk of diseases such as posterior staphyloma of the sclera and retinal detachment, and ultimately resulting in severe vision impairment. By reviewing the related literature at home and abroad in recent years, the paper systematically sorted out the relationship between the changes in axial length and fundus damage, deeply discussed the interacting mechanisms, aiming at providing reference for the prevention and treatment of myopia in children and adolescents, with the expectation of reducing the occurrence of complications of myopic fundus lesions, which has important practical significance for protecting the eye health of children and adolescents.