Children's painting refers to the works that children doodle or draw through imagination and free play after curious observation of the external world in childhood. The definition of children's painting has two meanings. On the one hand, it refers to pure pictures made entirely by children without the guidance of teachers; On the other hand, it refers to painting under the guidance of teachers while maintaining interest in painting on the previous basis. ? In essence, children's paintings reflect the process of children's cognition. With the improvement of language ability and ideological understanding, children will be full of curiosity about things around them. At this time, they need to express their feelings through painting, which is an expression of interest. In other words, the essence of children's painting is the natural display of interest, and interest is the internal motivation of children's painting. It can also be said that the essence of children's painting is children's self-expression and a kind of game for children. Children regard painting as an indispensable part of their games. Its basic function is to enlighten children's hearts and emotions, and it is a very important way to study children's psychological development. Therefore, when children have the desire to express their lives, they will produce paintings that really belong to them. Children's painting is a special stage for human beings to engage in artistic activities. It is accompanied by children's growth, reflects children's nature and shows children's thinking activities. It is a special visual language for children to express their thoughts and feelings. Children's paintings have distinct personality characteristics: innocence, boldness, exaggeration, romance and frankness. Children are unrestrained in painting, and there are no obstacles, which forms the unique childish, dreamy and even absurd meaning of children's painting. These characteristics directly reflect children's thinking and inner world. Therefore, when we watch children's paintings, we can strongly feel the beauty of childlike innocence and childishness embodied in children's paintings, which we can't feel in adult paintings. Children's paintings not only reflect children's psychological development level, but also promote children's mental growth. Painting plays an important role in promoting children's perception, memory, imagination and creative thinking.