A 1550nm all-fiber single-frequency pulsed fiber laser based on eye-safety spectral range was achieved in this paper.The laser adopts the single-frequency semiconductor laser with external cavity frequency stabilization technology as the seed source,whose line width is 1.8 kHz and power is 20 mW.First,the seed power was amplified by pre-amplifier,then pulse laser was obtained by acoustic optical modulator.Later two power amplifier was applied,and an line width 1.9 kHz single-frequency pulsed fiber laser was realized with average power of 521 mW,pulse width of 200 ns and repetition rate of 10 kHz.The laser pulse peak power was 260 W.Because an double-clad single mode fiber was applied in output end,the laser beam quality was keeped well.The whole fiber laser system employed the structure of cascading amplifying,and applied gain control technology in fiber amplifer.Thus the Stimulated Brillouin Scattering effect was suppression successfully,and the influence of noise to line width was eliminated in the amplifying process.Accordingly,an single-frequency pulse laser with stable line width was obtained.