Abstract: The paper use mainly ray casting algorithm to convert the 2D image to 3D image. We use tri-linear interpolation algorithm to calculate the color and opacity of the sampling in order to improve the accuracy of 3 D reconstruction. The algorithm caculates the accurate projective region of 3D regular data field based on the OpenGL library and its 3D view matrices. Consequently it reduces the amount of rays in ray casting algorithm. This method also computes shading tables for the data field in advance according to the light of phone illumination model. In addition, the regular implementation codes of the algorithm are optimized. These stategies work together to speed up the ray casting volume rendering algorithm effectively. The algorithm improve not only the accuracy of 3D reconstruction but also the effective of 3D reconstruction.