In order to calculate the effective operating range of a laser jammer,many factors which can influence the system performance must be considered.The operating range calculating model are built up and the current method for estimating operating range is summarized.Taking 1.06μm laser photoelectrical detector for instance,this paper analyzes laser propagation in atmosphere,discusses the estimating method for sparkle radius and atmosphere turbulence effects.The relationship between operating range and laser power and visible range is simulated.The results proved that this method can estimate the operating range of laser jamming system easily.It can be used to estimate the distance scope for field test,and also can be used to evaluate the performance of a laser jamming system under test.