High power laser device beam is detected and aligned with TMCM 351E device control board and a self-made automatic alignment procedures, and a set of novel optical monitoring alignment system is desigred. With the use of variable structure control algorithm, automatic extraction of the near and far field reference center and the spot center are achieved, and automatic alignment procedures are realized with high stability, high precision and high efficiency. Experiments are conducted on platform to verify the performance of the alignment system. Experimental results show that, compared to traditional method, the adjusted average error of spatial filter pinhole diameter is 0.9% in the monitoring collimation system, which can meet the precision requirement of far field adjusting collimation system (less than 5% of small hole diameter) and near field adjusting collimation system (less than 1% of small diameter). Stability test of 10 h shows that the control system has good stability with angle jitter of ±12.6 μrad. The system is verified in the high power laser device. The alignment time of eight pre-light road is less than 3 min and the alignment time of the main light path is less than 7 min.