To address the problem wherein the existing decode methods do not consider the effect of global illumination on decoding accuracy, this paper proposes a surface structured light decoding algorithm based on illumination intensity. First, the appropriate subhigh-frequency patterns from a series of encoded patterns are selected to estimate the ratio coefficient of the direct and global illumination intensities for a scene. Subsequently, the ratio coefficient is used to compute the direct and global light intensities of each pixel point. Finally, a decoding rule is constructed based on the direct and global light intensities, followed by three-dimensional reconstruction. Comparative experimental results show that the proposed decoding algorithm can effectively improve both the decoding accuracy and quality of the reconstructed point cloud.