Abstract: In order to establish a dynamic prediction and 3D visualization model for forest fire spread, a Wang Zhengfei3D CA realtime model was proposed. Both physical rules and global factors for forest fire spread were considered in this modified model, which involved wind direction, wind velocity, temperature, terrain slope and vegetation type on the basis of Wang Zhengfeis experiential initial fire spread velocity, and the transformation rule was established according to energy exchanged in cells. Some experiments in southwestern fireprone areas in China had been done in this paper and the process of fire spread and achieves vector boundary were simulated in multiconstraint conditions. Results show that the modified model is feasible and effective with a small quantity of input parameters, could simulate forest fire under different conditions and rapidly predict a developing fire.