Abstract: 3D-HEVC is a newly emerging stereo video coding standard, it adopted the Multi-view plus depth format, which requires to encode the texture map and corresponding depth map at the same time. 3D-HEVC also developed a series of new methods for depth map. To reduce computational burden of depth map, we propose an efficient fast algorithm for depth map intra coding based on the quad-tree splitting structure and intra prediction process. We apply Otsu’s method to each depth level to get the maximum inter class variance, and analyse the correlation between maximum inter class variance and optimal optimum partition result. We use Otsu’s method to stop further splitting process of smooth CUs and simplify the intra prediction process. We further optimize our algorithms by using rate distortion cost and the correlation between different layers of CUs. Experimental results show that our proposed algorithm can save 40.1% time consumption on average with negligible loss of coding performance.