Sea-scattered echo is the main interference for laser detection system in low-altitude sea-skimming target detection.Based on Pierson-Moscowitz sea wave spectrum,a geometric model of rough sea surface at different wind speeds is established,which is used as the height field of sea surface.By dividing sea surface into facets,and based on Cox-Munk statistical model on sea wave slope,the reflected echo of facet is calculated out,and a light scattering model of rough sea surface is established.By use of the model,a simulating calculation of the scattering light distribution of cone-field incident laser beam and the receiving power of detector is made.The results show that the scattering light distribution of rough sea surface is related with the incident angle and wind speed.For incident laser beam with cone-field,the scattering light is mainly distributed around the stereoscopic space in the mirror-image direction of incident beam.The smaller the wind speed,the more concentrated the distribution of scattering light; the greater the wind speed,the more dispersed the distribution.It provides an important theoretical basis for analysis of laser beam scattering properties and calculation of scattered echo from rough sea surface.