A master oscillator power-amplifier (MOPA) type wavelength tunable high-power single-frequency narrow linewidth fiber laser is designed and implemented,in which the oscillation stage adopts a ring-cavity structure,and the tunable fiber Fabry-Perot (FP) filter and self-induction fiber Bragg grating (FBG) filter are used to realize the output of a single-frequency narrow linewidth laser,and the amplification stage is double-cladding gain fiber pumped by a high-power multi-mode laser diode.The 2 m erbium-doped fiber (EDF) pumped by a 980 nm laser diode is used as the gain medium,the dynamic FBG generated by the tunable fiber FP filter and the 2 m unpumped erbium-doped fiber is used as the narrowband filtering device,the 4 m erbium-ytterbium co-doped double-cladding fiber (EYDF) is used as the laser amplification stage gain medium.The wavelength tunable narrow linewidth single-frequency laser output in the range of 1524.35—1566.10 nm is realized,with an average linewidth of 12.7 kHz and a laser output power of 1.16 W,which significantly improves the output power of the tunable narrow linewidth laser.