In recent years, Hollywood has attached increasing importance to adapting fairy tale themes into films. As classic works of world fairy tales, the Grimm’s Fairy Tales have been repeatedly adapted into animated or live-action films, such as Red Riding Hood, Snow White and the Huntsman, Cinderella, The Frog Prince and Maleficent, all of which are well-loved by audiences. Among them, Sleeping Beauty is one of the classics in the collection of fairy tales by the Brothers Grimm. In 1959, Disney of the United States released an animated film adapted from the fairy tale of the same name, whose plot was largely consistent with the original story. However, the 2014 Disney live-action film Maleficent made a subversive adaptation of Sleeping Beauty and achieved certain success. Then, did the film adapt the content or the form? Based on the morphological theory of stories proposed by Vladimir Propp, a Russian folklorist and representative figure of formalism, this paper takes Maleficent as an example, compares it with the story of Sleeping Beauty, and examines the role of character functions, hoping to find the rules of film adaptation, namely the influence of variable and invariable factors on the story.