Childhood is a relatively large period of time, and can be divided into the following two phases: I. Preschool period: from the age of 3 weeks to 6 to 7 years old before entering elementary school is the preschool period. Second, the school-age period: since the beginning of elementary school (6 years old to 7 years old) to the pre-pubertal period for the school-age period. During this period, children’s physical growth rate is relatively slow, except for the reproductive system, the appearance of all systems and organs are close to that of adults. This is a period of rapid development of language, thinking, movement, and neuropsychiatric development in children. The development of language, memory, imagination, fine motor, etc. is accelerated, curiosity about the external environment, good imitation, and tends to transition to intelligent development. As they grow older and interact more with their surroundings, their perceptions and emotions about objective things diversify, and they easily develop a sense of sympathy, honor and trust, and under proper guidance, they can gradually distinguish between good and bad, like and dislike. Language ability and expression ability are developing by leaps and bounds.