Abstract: In accordance with the strict demand on the laser beam direction at high power solid-state lasers,the angle drift is measured at sub-laser in XG-Ⅱ.The micron quantity microscope is used in the experiment.The internal and external cause which bring about the angle drift are considered at the process of analysis,the data is analysed and handled at root-mean-square.The result is that the angle drift of sub-laser in XG-Ⅱ is 1.55″±0.72″,it a ttains the design objective of being smaller than 2″ and contents with the requirement of shooting practice.