Abstract: In order to increase the conversion efficiency of a multi-disk laser at Brewster angle,the main elements affecting the efficiency were analyzed theoretically and verified by means of experiments.A series of datum about the relation of output energy and intracavity loss were gained.The results indicated that inherence loss due to multi-disk configuration led to low laser efficiency.The dynamic loss limited the ability of continuous laser output,and the pump loss brought a certain effect on the laser efficiency.