In this paper，a computational model for simulating turbulent dispersion of droplets in two-phase flow spray field is presented. Liquid spray size distribution is divided into some droplets groups，which has a initial mass mean diameter differing from each other.All of the droplets in same group have the same diameters，chemical components，temperature and velocity. The droplet turbulent disperse in the same group are considered in the calculation. By comparisons it is demonstrated that calculated result is basically identical with tested result.