Aiming at the low efficiency of sampling, big memory consumption, slow speed of drawing shortcomings of traditional volume rendering algorithm, this paper puts forward the light projection algorithm based on linear octree is used for real cloud image visualization. This method first by linear octree optimize traditional casting algorithm and the storage speed, and combining the Blinn-Phong illumination model enhance colour rendering of ividual element , then use the synthesis formula for cumulative pixel values, calculated by use of light and shade effect shows that the boundary of the cloud ,and realize the cloud visualization. Experimental simulation results show that the effectiveness of the proposed algorithm about enhancing rendering effect and rendering speed.