Abstract: In order to obtain stable laser beam,random deviations of light beams should be corrected.Taking the progress of adjusting direction drifts of pulse laser beam with fast steering mirrors in the beam delivery system as an example,an algorithm based on moving average(MA) correction mechanism was used to simulate the correction outcomes with or without ground jitters.MA and moving standard deviation(MSD) are used to evaluate the correction effects.The results indicate that this algorithm can control the position excursions on the plane of beam delivery system caused by the direction drifts of laser beam effectively,and the MA corrected has a big jump between n~2n pulses,for example,the optimal MA can be reduced to n-1/2 times(n is pulse numbers in a window).At the same time,there is a sudden decline in MSD between n~2n pulses,and soon afterwards,MSD is going to be sticking.Meanwhile,the drifts can be restrained while loading the ground jitters,and the dropping amplitude is bigger than without the ground jitters.The results show that the key of applications lies in construction of the appropriate corrections.What is more,this algorithm which is practical can achieve real-time control of direction drifts.