Abstract: Based on the discussion of the law of the interaction between opticfield and fluidfield, this paper uses the physical model of highenergy laser beam crossing through the two dimension supersonic free shot flow. We obtained density map and OPD map of fluid field and far field distribution of laser beam. We discussed: the disturbance of the fluidfield caused by radiation heating and the changing of laser beam intensity after the beam passing through the fluid field and propagating 2km in the still atmosphere. The results show that there's a distinct influence of fluidfield on opticfield. Also we got that in studying the interaction of supersonic free shot fluidfield with highenergy laser we can neglect the radiation heating when the air is not ionized．