The invention relates to a cylinder-shaped integral fiber coolant mechanism used for the fiber refrigeration in a superpower fiber laser, which is characterized in that the device comprises a multichannel fiber refrigeration inner-cylinder and a multichannel fiber refrigeration outer-cylinder; an inner-cylinder spiral trace semicircular-groove is arranged on the outer surface of the multichannel fiber refrigeration inner-cylinder, and a plurality of inner-cylinder refrigeration water channels are arranged inside a body; an inner-cylinder water inlet and an inner-cylinder water outlet are positioned at the two ends of the inner-cylinder refrigeration water channels respectively; a plurality of outer-cylinder refrigeration water channels are arranged on a cylinder body of the multichannel fiber refrigeration outer-cylinder, and an outer-cylinder water inlet and an outer-cylinder water outlet are arranged at the two ends of the outer-cylinder refrigeration water channels; an outer-cylinder spiral trace semicircular-groove corresponding to the inner-cylinder spiral trace semicircular-groove is arranged on an inner wall of the multichannel fiber refrigeration outer-cylinder for the closed fixation of fibers so as to lead the fibers to form a well heat conduction relation with the multichannel fiber refrigeration inner-cylinder and the multichannel fiber refrigeration outer-cylinder. The cylinder-shaped integral fiber coolant mechanism can enable the superpower fiber laser to operate within a normal temperature range.