In 2009, the Government of China incorporated the prevention and treatment of mental illness in children and adolescents into the national basic public health care services. What is the mental health situation of children and adolescents in China? According to the World Health Organization, youth suicide caused by mental disorders and psychological problems is the third leading cause of death among young people worldwide. There are 360 million children and adolescents in China, and the incidence of mental illness in this population group remains high, so their mental health situation is worrying. According to statistics, the clinical bases of China Children’s Medical Research Center receive an average of more than 500 children with mental illness every day, and about 160,000 patients a year. The 19th International Academic Conference on Child and Adolescent Psychiatry and Related Disciplines (held on June 2, 2010) released data show that: the current prevalence of child and adolescent mental illness in China has exceeded the international average of 15-20%, children and adolescents under 17 years of age, there are at least 30 million people suffering from a variety of emotional disorders, left-behind children, The psychological and behavioral problems of left-behind children, single-parent children and only children are particularly prominent. What are the reasons for the high incidence of mental illness among children and adolescents in China? There are five biological reasons: 1, adolescent mental development neurotransmitters, dopamine, sex hormones, etc., are in an unstable release, or immature developmental stage. Especially rebellious teenagers, neurotransmitters released rapidly, according to Freud’s interpretation of mental illness: “Libido” in the infinite energy, youth behavioral manifestations and subconscious conflict within the self. Lack of knowledge of their own hormone and neurotransmitter characteristics. Lack of sexual knowledge, resulting in teenagers shy to discuss sexual knowledge with their parents, become introverted, shy, no self-awareness, short-lived social horror. 3, a variety of nutrients, vitamins and minerals, only care about physical development, regardless of brain and nerve development, for seafood, lecithin and other lack of. 4, genetic factors, hormone secretion genes from parents, and the family environment, diet structure, the body outside the direct impact. 5, the psychoneurological development process of each baby to children are basically the same (not just seven flip eight crawl), each process of deficiency and excess, Freud believes that its in adulthood, especially after encountering emergency events appear compensation mechanism, which appeared with the reality of the disconnect and emotional incoherence syndrome symptoms.