Children with low IQ (mental retardation) are mainly characterized by impaired daily adaptability, delayed speech development, poor comprehension and analytical skills, and learning difficulties. Children with mild intellectual developmental disorders are mainly characterized by delayed speech development, poor vocabulary, poor comprehension and analytical skills, and underdeveloped abstract thinking. These children are able to take care of their own lives independently, eating, dressing, washing, urinating and defecating without being affected. They are usually diagnosed because of unsatisfactory academic performance (or even repeating a grade), and are found by their teachers and advised by their parents to seek medical attention. The self-care ability of children with moderate/severe/very severe intellectual developmental disorders is often significantly impaired and can be easily detected. These children often have congenital genetic disorders, perinatal harmful factors, and neonatal/childhood illnesses. Children with poor adaptability and learning difficulties should seek prompt medical attention, and after the diagnosis has been made, they should undergo relevant rehabilitation training and education in the rehabilitation department of a regular hospital.