The invention relates to an adjusting device of an optical fiber polarization controller, which belongs to the technical field of optical fiber communication. The adjusting device comprises the optical fiber polarization controller, an engraving thumbwheel, a locking fixture, an external panel and a base bracket. According to the adjusting device, the engraving thumbwheel which is exposed out of the external panel is adjusted to rotate, so as to drive an optical fiber ring piece to rotate, external adjustment and quantitative continuous control of the optical fiber ring piece of the optical fiber polarization controller are realized, the repeatability and the adjusting efficiency of the optical fiber polarization controller are increased, and the locking fixture is adopted, so that the long-term working stability of the optical fiber polarization controller is improved. Additionally, the adjusting device of the optical fiber polarization controller provided by the invention has the characteristics of adjusting space saving and low cost, and the adjusting device is especially suitable for controlling the polarization state of light waves in laboratories.