We　present　a　four-rod　series　resonator　CW　Nd:YAG　laser　for　the　requirement　of　industrial　application　in　this　paper.　The　symmetrical　resonator　laser　has　been　developed　and　is　rated　at　2105　W　output　power　with　beam　parameter　product　of　24　mm·mrad.　The　system＇s　total　electro-optics　efficiency　of　lamp　pumped　YAG　crystal　is　as　high　as　3.5%.　The　main　factors　which　affect　operation　of　high　power　solid-state　laser　module　are　different　positions　and　thermal　focal　lengths　of　crystal　rods,　and　so　on.　These　factors　are　theoretically　analyzed.　Conclusions　are　drawn　that　the　resonator　would　have　the　biggest　steady　range　when　the　rods　in　it　are　symmetrically　arranged　and　thermal　focal　lengths　of　the　rods　being　not　matched　can　be　compensated　by　adjusting　input　power　of　laser　system.