Based on low-altitude laser atmospheric transmission models, distributions of scattering irradiance of 1.06 μm laser in atmospheric transmission are calculated. By comparing with echo signal energy of lasers at the same conditions, calculation results are found to be different from the results of theoretical analysis. The reason is that single pulse characteristics of lasers are not considered. By improving the formulas of laser scattering energy at single pulse operation mode, the calculation accuracy of scattering detection is enhanced.