Based　on　the　technology　of　wavelength　beam　combining,　this　paper　applies　the　diffraction　of　the　grating　and　the　feedback　of　the　external　cavity　to　demonstrate　all　elements　of　the　diode　laser　array　(LDA)　locked　in　different　wavelength,　the　neighboring　emitters　having　little　difference　in　output　wavelength.　The　output　beam　from　the　external　cavity　coupler　mirror　is　nearly　parallel,　the　combined　beam　has　the　same　beam　quality　as　the　beam　of　single　element　of　the　LDA,　but　the　brightness　of　the　combined　beam　grows　with　the　number　of　the　LDA　element.　The　1　cm　linear　array　was　used　in　the　experiment,　consisting　of　49　wide-aperture　diodes　with　a　diode　width　of　100　μm　and　a　fill　factor　of　0.5.　The　combined　beam　power　is　2.39　W,　the　wavelength　spread　is　about　27　nm,　the　diameter　of　a　circle　spot　is　0.08　mm,　and　the　field　divergence　angle　is　1.2　mrad　in　both　directions　in　a　single　cavity.　The　combined　beam　quality　factor　is　calculated　as　28,　which　is　the　same　as　that　of　a　single　element　of　the　LDA.