(1) The basic knowledge of preschool children's development, including: the law of children's psychological change and development, the time, sequence and trend of various psychological phenomena, and the main characteristics of psychological development at all ages; (2) The causes of children's psychological changes lay the foundation for correctly understanding and treating some "weird" behaviors of children; (3) Master the methods of studying preschool children's psychology, such as conversation, experiment and observation. (4) Establish a correct view of modern children; (5) Factors affecting children's personality development and so on.