By using the four-dimension code of laser propagating in atmosphere and compensation of adaptive optics, the focused flat beam with different transmitted condition is computed. The results show that the parameter D/r₀ could do well in describing the turbulence strength in weak turbulence condition when the adaptive optics is open, and the Strehl ratio(SR) could be written as SR=exp[－0.2(D/r₀)²], the quality factor of laser beam could be write as, β²=1+1.2(D/r₀)². When the strength of turbulence or the length of propagating is increased, the effect of scintillation and the branch points on the laser beam must be considered,and the parameter D/r₀ is out of use. In addition, there is a threshold in compensation of adaptive optics on laser beam with different transmitted conditions.