Including　constant,　linear　function　and　exponential　function,　three　good　guess　functions　of　forward　signal　power　are　developed　to　deal　with　the　difficulty　of　setting　suitable　estimates　in　the　multipoint　pumping　Yb3+-doped　double-cladding　fiber　lasers　(YDCFLs)　model　with　boundary　conditions　using　MATLAB　BVP　solvers.　Simulation　results　show　that　three　good　guess　functions　can　get　rapidly　the　exact　values　of　YDCFLs　after　only　one　iteration　times.　Among　three　good　guess　functions,　conversion　efficiency　critical　guesses　of　linear　functions　are　more　stable　than　those　of　constant　and　exponential　functions　at　different　fiber　lengths.　Furthermore,　the　more　pump　points,　the　smaller　fluctuations　of　conversion　efficiency　critical　guesses　in　linear　functions　at　different　fiber　lengths.　Conversion　efficiency　critical　guesses　of　linear　functions　keep　small　fluctuations　with　the　increases　of　pump　powers　at　different　points　pump.　(C)　2015　Elsevier　GmbH.　All　rights　reserved.