An image capturing apparatus and a photo composition method thereof are proposed. The method is adapted to an image capturing apparatus having a first lens and a depth sensor and includes the following steps. First, a preview frame of a scene is obtained by using the first lens, and depth information of the scene is obtained by using the depth sensor. Next, scene analysis is performed on the preview frame according to the depth information so as to generate a scene analysis result. Next, whether the preview frame satisfies a photo composition requirement is determined according to the scene analysis result and a corresponding photo composition rule. If yes, the first lens is controlled to capture the preview frame; if no, a photo composition suggestion corresponding to the scene is provided according to the photo composition rule corresponding to the scene analysis result.