Children with strabismus, including congenital strabismus, have early onset and great impact on vision. The impact is even greater when combined with various vertical muscle paralysis. Because of the early onset, the young age of the child and the inability to cooperate with the examination, the clinical examination and treatment are more complicated and difficult. Although there are many methods of strabismus examination, including synoptic examination, visual field arc examination, trigeminal examination, and so on. However, the cooperation of children is poor. Therefore, the existing examination methods are actually rarely suitable for children of low age or patients with low intelligence (including adults). Even ophthalmologists specializing in eye muscles often find it very difficult to work with such patients. The progress of computer science has made the acquisition of images easy and fast. In order to solve this problem in practice, we discuss the methods of diagnosis and treatment of complex strabismus in preschool children. The director of the ophthalmology department of Guangzhou Children’s Hospital, Xiang Daoman, supported the research of a computer-aided objective and quantitative diagnosis technique for children’s strabismus to obtain the number of strabismus objectively, and by introducing this technique in the clinic, the age of surgery for children with strabismus who need surgery is greatly advanced, and the success rate of surgery can reach 95% at one time.