Developmental delay is often the result of babies and toddlers who, at a certain stage, lag behind in their learning and cognitive development compared to children of the same age, and are unable to meet normal developmental standards. The causes of mental retardation are varied, and if there is substantial damage to the baby’s brain, the degree of developmental delay is more severe, and a complete cure will be very difficult. Therefore, it is necessary for parents to recognize the problem of developmental delay as early as possible, and to treat the child correctly during the golden period of brain development (before the age of 3), which will be very beneficial to the child’s future intellectual development. If a child is delayed due to external factors or physical weakness, he or she can catch up with babies of the same age as long as the parents give him or her more help and correction. Parents should create a better learning environment for their children, communicate with their babies more often, and pay active attention to their babies’ learning within a certain period of time, such as crawling, sitting and walking, talking and movement. Parents should repeat the training for babies with poor learning ability and encourage them more. In addition, babies should be allowed to have more contact with the outside world and nature, which can help enhance their enthusiasm and motivation to learn. Mental retardation can be regulated and compensated by enhanced training if it is caused by untimely parental education. If the child has brain damage problems, he or she should see an early childhood neurologist in the hospital for proper treatment.