Er,Eu:YAlO3　(abbr.　as　Er,Eu:YAP)　crystal　was　grown　by　the　Czochralski　technique　for　the　first　time.　Its　absorption　and　fluorescence　spectra　as　well　as　the　fluorescence　decay　curves　were　measured　and　investigated.　The　spectral　parameters　including　absorption　cross-section　and　emission　cross-section　were　calculated.　It　is　found　that　the　crystal　has　short　lifetimes　at　4I13/2　and　4I11/2　levels,　large　absorption　cross-section　at　974　nm　and　790　nm,　and　large　stimulated　emission　cross-section　at　2704　nm.　The　co-dopant　Eu3+　decreases　the　fluorescence　lifetime　of　4I11/2　level　from　400　μs　to　59.35　μs,　and　thus　inhibits　the　self-termination　effect　of　~2.7　μm　in　some　degree.　We　develop　a　theoretical　model　that　simulates　the　laser　characteristics　of　Er,Eu:YAP　crystal　numerically.　Based　on　Er3+-Eu3+　energy　level　diagrams,　the　rate　equation　model　was　built　and　discussed.　It　was　found　that:　when　the　pump　rate　increases　gradually,　the　laser　quantum　efficiency　reaches　to　its　upper　limit　with　a　fixed　value　2-p2,　and　this　value　is　1.35　for　Er,Eu:YAP　crystal.　The　results　show　that　Er,Eu:YAP　crystal　is　an　excellent　material　candidate　for　~2.7　μm　laser.　©　2018　Elsevier　B.V.