A lens barrel is provided that includes an image optical system with an optical axis. The lens barrel has a first lens, a second lens, a guide shaft, and a driving unit, an adjusting mechanism, and a base frame. The adjusting mechanism is coupled to the guide shaft and has a first and a second portion. The first portion is deflectable and supports one end of the guide shaft. The second portion is configured to press against the first portion to deflect the first portion at an angle relative to the optical axis. The adjusting mechanism is configured to adjust the position of the guide shaft. The guide shaft is arranged to at least partially overlap the driving unit in the circumferential direction around the optical axis, and the first lens is arranged to at least partially overlap the adjusting mechanism in the radial direction relative to the optical axis.