The invention discloses an optical-fiber laser device. The optical-fiber laser device includes a saturable absorber device, ytterbium-doped optical fibers, a wavelength division multiplexer, a pumpingsource, single-mode optical fibers, a ray isolator, a polarization controller and a coupler; the saturable absorber device is melted in a laser cavity in the optical-fiber laser device, and in this way, the tunable accuracy of the wavelength of laser output by the optical-fiber laser device can be improved by adjusting the curving rate of the saturable absorber device. By the adoption of the saturable absorber device and the optical-fiber laser device, through a simple structure, the purpose can be achieved that the wavelength of the output pulse laser is tunable.