As a unique artistic form of film and television, animation has a lot of rich and excellent works. Among them, there are short animation works and full-length animation works with detailed narration. Animated short films and the long animation not only differ in length, but also have their own characteristics in script structure. Animated short films have compelling content and form, simplified story structure and emotional core full of charm. The story of animated feature films is relatively complete, closely connected with each other, and the plot usually revolves around the central theme layer by layer. This paper analyzes the structural difference between animated short film and feature film by understanding the concept of structure of drama.