文章从影像本体论的问题出发,围绕“电影是什么”这个问题做了一系列的讨论和研究,从照相写实主义、移动影像、表演特征和电影的维度四个角度出发,通过电影与音乐、绘画、雕塑、戏剧等多种艺术形式的对比,探讨了定义移动影像的五个必要条件,也列出了与以前传统电影理论的对比、更好地定义了移动影像。这能够为之后的电影研究提供更好的借鉴和更扎实的理论基础,具有重要的理论意义。 Based on the issue of image ontology, the article makes a series of discussions and studies around the issue of “What is the film?”. From the four aspects of photorealism, moving images, performance characteristics and the dimension of the film, Music, painting, sculpture, drama and many other forms of art, explores the five necessary conditions for the definition of moving images, and also lists the comparison with the previous traditional movie theory to better define the moving images. This can provide a better reference and a more solid theoretical basis for the later film research, which has important theoretical significance.