The clues of the article can be classified according to different categories. The common categories include: plot clues, character clues, theme clues, and environmental clues. The plot clue refers to the plot clue that runs through the whole novel, including the relationship between the characters, conflict, turning point and ending. It is the core of the plot of the novel. The arrangement and development of the clue can promote the development of the story. Character clues refer to the character clues that run through the novel, including the relationship between the main characters and the secondary characters, character, action, fate, etc. The relationship between the secondary characters, character, fate, etc. can be shaped through the arrangement and development of the character clues. Thematic clues refer to the theme of the novel, including the theme, thoughts, emotions and symbols. The theme of the novel can be expressed through the arrangement and development of the clues. The environmental clues referred to the environmental clues that ran through the novel, including the geography, climate, social background, and the environment in which the characters lived. The environment of the novel could be expressed through the arrangement and development of the environmental clues.