The invention is a kind of all otpical form dresser based on the saganuke ring, which includes an input end, an output end, a fiber coupler, and a fiber ring. The character lies in: there sets the first variable refractive index lenticule, a polarizing disc, the second variable refractive index lenticule and the Faraday polarization apparatus, and fiber coupler on the input end of the signal beam path; there also sets a control beam path, on which there sets a delay device, variable rejector, convex lens, a fiber segment, a three-circle polarization controller, the first WDM coupler and the second WDM coupler. One end of the fiber segment is at the focus of the convex lends, another end of the fiber segment is connected to the fiber ring through the first WDM coupler, there sets the second WMD coupler on the fiber ring with interval L to the first WDM coupler, and the L is little than the semicircle of the fiber ring, the three-circle polarization controller is set on the fiber segment.