An all-fiber 1 150 nm long-wavelength fiber laser oscillator was demonstrated by using a pairs of fiber brag grating as the laser cavity, a piece of Yb-doped as the gain media and a 976 nm laser diode as the pump source. 1 150 nm band single-mode fiber laser with max output power of 12.7 W is obtained at room temperature and the optical-to-optical conversion efficiency is up to 42.33%. The central wavelength is 1 150.48 nm, the 3 dB spectral width is 0.45 nm and the optical signal-to-noise ratio is 38 dB. The research results will make a contribution to the further development of high-power 1 150 nm long-wavelength fiber laser oscillator.