A lamp structure has a film-coated glass tube fixed by a body and a fixing element. The film-coated glass tube has 3D images film-coated on an inner wall for projection. A hollow tube passing through the film-coated glass tube is connected to a lighting bulb at a top thereof and has a projecting bulb connected in a middle section thereof for projection on the film-coated glass tube. Thereby the present invention is able to display 3D images by projection with a strongly fixed structure of the film-coated glass tube.