Children’s mental retardation, refers to the developmental period of the individual, the general intellectual function is significantly lower than the level of the same age, accompanied by adaptive behavior defects, mainly manifested as perception, memory, language, thinking disorders, mainly the following: 1, mild patients clinical manifestations are generally no physical abnormalities, language development is delayed, the ability to adapt to society is lower than normal level, can social interaction, with practical skills, such as life They can take care of themselves and do simple labor or technical operations; their learning ability, skills and creativity are worse than normal, and their ability to read, write, calculate and think abstractly is worse than that of children of the same age; they have learning difficulties, but after special education, their intelligence level and social adaptability can be improved; 2. The children with moderate level of mental ability can take care of part of their daily life, can do simple household chores, but their language, motor and skill abilities are obviously weaker than the normal level of their age, have poor reading and calculation skills, poor comprehension, lack of learning ability for learning tasks, cannot live completely independently in adult life, and a few of them have physical developmental defects and neurological abnormalities. In severe cases, they cannot sit, stand, or walk, and cannot receive education, often accompanied by epilepsy and congenital malformations.