In order to study the effect of temperature on the output performance of fiber lasers, a self-seeded linear cavity fiber laser is constructed. The laser uses erbium-doped fiber as the gain medium, and uses fiber Bragg grating （FBG） and fiber ring mirror to form a linear laser cavity. The laser is experimentally studied by changing the temperature of the core device in the cavity. The experimental results show that the laser wavelength increases linearly with the increase of temperature. Compared with the change of the output wavelength of the laser when the FBG itself is heated, the laser wavelength is redshifted by 0.052 43 nm. When the temperature is increased from 25℃ to 55 ℃, the output conversion efficiency of the laser is reduced by 4.878%, and the output power is reduced by 33%.