The synchronous belt-driven leather tape measure related to the field of measuring tools is for the well-known leather tape measure whose internal structure is combined with a spring reel and a rule reel. If the measuring size of the leather tape is enlarged, the radial direction becomes larger, and there is a kind of leather tape designed for the technical problem of inflexible use. The main points of the design are that the front shell and the rear shell are curved and long in the horizontal direction and multiple arc-shaped short bodies in the longitudinal direction; the front shell and the rear shell are equipped with a timing belt, a large gear, a small gear, a rotating drum, and a rotating wheel; One section of the big gear and the timing belt is set in the rotating drum, and the other section of the small gear and the timing belt is set on the pin of the pinion extension of the rotating wheel; the leather tape is wound in the groove of the rotating wheel; the drum and rotating The wheels are sleeved on the corresponding pins of the front shell and the rear shell. The aspect ratio of the leather tape with this structure changes greatly, it is comfortable and dexterous to use, and the winding is more stable. It is an ideal leather tape.