Adjusting device and wrist band

The utility model discloses an adjusting device and a wrist band comprising the adjusting device; the adjusting device is used for adjusting the size of the main body of the wrist band; the adjusting device comprises a shell, an adjusting part and a locating part, wherein the adjusting part is fixedly attached on the surface at one end of the main body; the locating part is matched with the adjusting part to locate the opposite position of the main body and the shell; the main body comprises an adjusting end and an annular wearing end extending from the adjusting end; the adjusting end is installed in the shell and can elastically stretch in the shell; the adjusting part is strip-shaped; a plurality of toothed grooves are arranged on the adjusting part; the locating part is fixedly connected with the shell; one end of the locating part is bended to form a clamping hook; when the main body is adjusted properly, the clamping hook is embedded in the corresponding toothed grooves, so that the main body is located; because the toothed grooves and the clamping hook are matched, the size of the wrist band can be adjusted conveniently and rapidly; furthermore, the adjusting device is simple in structure and low in cost.