The cover picture of a picture book shows the content and characteristics of the work through painting. It can present the story clues of the work by depicting the main characters, key scenes or important plots, so that readers can feel the tone and emotional atmosphere of the story at first sight. At the same time, the cover picture can also show the painting style, such as using different painting techniques such as watercolor, oil painting or sketch, as well as different painting styles such as realism, comics or abstraction. Through the cover picture, readers can have a preliminary understanding and expectation of the content and style of the picture book.