This article takes the study of children's literature as a threshold for change, enabling readers to explore the surrounding reality, imagine other worlds and understand other perspectives. Based on the concept of children’s cognitive development, it is divided into four stages ―pre-reading, fantastic stage, fantastic-realistic stage and aesthetics stage― reading becomes a resource to combine fantasy and experience where the mirror is a very illuminating element, easy to produce hundreds of interpretations and applications, such as Brother Grimm (Grimm.s Snow White), Lewis Carroll (Lewis Carroll) " The Through the Mirror Glass, Michael Ende's "Endless Story" and JK Rowling's "Philosophy Stone" and so on. Therefore, when young readers move from one stage to another, the mirror becomes more symbolic and complex. They are faced with the discovery of self and the other self, as well as the so-called confrontation between elementary and elementary. The second world, reality and wonder