Abstract: To study the forward-scattering effect on underwater laser imaging, a forward-scattering model of underwater laser imaging system based on radiative transfer theory was established. The forward-scattering influence coefficient was proposed, and the analytical expression of the coefficient and the forward-scattering power was given. The variation of the forward-scattering power and influence coefficient with exploration depth and water attenuation coefficient was attained using Matlab, which proved that the effect of asymmetry factor on underwater imaging quality was large.