Abstract: Thermal induced distortion in the gain element is the main obstacle to be overcome in the scaling of solid-state lasers to very high output powers.In order to compensate the aberration,the method of using an intra-cavity deformable mirror was carried out.The intra-cavity configuration was change when the deformable mirror was input the voltage.A referenced light from out-cavity was used to get across the intra-cavity.The effect of the intra-cavity aberration to the referenced light could be detected with a wavefront detector and was compensated by using the deformable mirror.The experimental results indicate the intra-cavity aberration was effectively compensated and the output power and beam quality were improved.