An illumination device is including an illumination body and a hollow sleeve. A light emitting element and a transparent sheet is disposed in the illumination body. A first convex lens is disposed in the hollow sleeve. The light emitting element, the transparent sheet, and the first convex lens are arranged sequentially along a moving direction. When the hollow sleeve is operated to move along the moving direction, the first convex lens is moved with respect to the light emitting element and the transparent sheet, and the projection facula is changed from presenting a light source pattern of the light emitting element to a predetermined pattern of transparent sheet.