In　order　to　research　high-power　multi-position-pumped　fiber　lasers,　the　theoretical　analysis　was　presented　based　on　the　rate　equations　and　boundary　conditions　of　Yb-doped　double-clad　fiber　lasers.　All-fiber　laser　is　built　with　the　self-made　cascaded　couplers.　In　the　experiment,　the　pump　efficiency　of　a　single　coupler　is　96%,　pump　transmissiom　loss　is　10%,　signal　loss　of　the　couplers　are　0.87　dB　and　0.18　dB　respectively.　In　the　structure　of　linear　cavity,　the　optical　conversion　of　forward　pump　is　69%,　lower　to　the　backward　pump　of　70%　optical　conversion,　consistent　with　theoretical　simulations;　in　the　two-end　pump,　single　input　pump　power　of　975　nm　is　110　W,　the　output　power　is　311　W　with　the　central　wavelength　of　1080　nm,　spectral　width　is　1.6　nm,　the　optical-optical　conversion　is　70%,　M2~1.3.　The　results　have　shown　that　the　output　power　of　laser　will　continue　to　increase　with　the　increase　of　the　pump　power　or　the　number　of　couplers.　©,　2015,　Chinese　Optical　Society.　All　right　reserved.