In this paper,the method to simulate the combined effect of jittering and thermal blooming of laser beams propagating in the atmosphere is discussed.If the jitter frequency is much less or much bigger than the thermal blooming frequency,the convolution method is used to simulate the combined effect of jittering and thermal blooming,otherwise Monte Carlo method is used to simulate the combined effect of jittering and thermal blooming.The far-field parameters of the focused Gauss beam propagating in the atmosphere are calculated out.The results agree well with those obtained from empirical expression.