A　high-power　narrow-bandwidth　all-fiber　thulium-doped　silica　fiber　master　oscillator　power　amplifier　(MOPA)　system　that　consists　of　a　low　power　thulium-doped　continuous　wave　fiber　laser　seed　and　two-stage　thulium-doped　double-clad　fiber　amplifiers　pumped　by　fiber-pigtailed　multimode　diodes　at　790　nm　is　reported.　The　center　wavelength　of　the　fiber　laser　is　1963　nm　and　the　3　dB　bandwidth　is　0.24　nm.　The　maximum　output　power　is　22　W　at　a　slope　efficiency　of　44%　with　respect　to　the　launched　pump　power.