Cellular automaton and multiple scattering are the more important technologies for generating cloud in the phase of modeling and rendering. Cellular automaton model gets a balance between physical model and procedural model which can make high speed and high quality clouds. Multiple scattering simulates the cloud scattering even more truly. In this paper, we will supply an algorithm which combines the above two technologies together to generate the real-time dynamic clouds. We hope using their strong suit to generate the real-time dynamic clouds. And through the cell?s state-changing equation we model the cloud?s movement by wind. Impostor is used to accelerate the rendering. All above get a better result of cloud?s real-time movement and realization.