Abstract: This invention provides a method for obtaining ear drum standard image and the design of related otoscope and software, which includes the following steps: First, moving an otoscope with a circle sight to a target position in ear canal, and capturing an ear drum image; Then, choosing an ear drum region from the ear drum image, and calculating an area overlapping between the circle sight and the ear drum region. If the area does not satisfy a standard value, moving the otoscope to another target position, and repeating above steps; otherwise, choosing the ear drum image to be an ear drum standard image.