Vygotsky's theory of psychological development clarifies the important role of teachers in schools and fully affirms the important position of children as the main body of their own activities in education. The role of teachers lies in how to use the great possibility of social environment to guide and guide children who live and behave in them. When Vygotsky studied the relationship between teaching and development, he put forward three important issues, namely "the nearest development area", "teaching should be ahead of development" and "the best period for learning".