To meet the demand of single-user independent authentication when multi-users share copyright of 3D model, the work proposes a 3D point cloud model with a high robustness multiple blind watermarking algorithm combined with CDMA technology. Different Walsh codes were assigned to different users. Walsh codes were also used to encode individual binary watermark image. Then mixed watermark signal was obtained. The 3D point cloud model was treated by affine invariant processing. And the vertex was coordinated into spherical coordinate system. The angular values were sequenced in ascending order. Then the vertex to the center of gravity from the composition was selected as a watermark embedded object. By wavelet transform, multi-channel mixing watermark was embedded in the diagonal direction of the high frequency part. Through the inverse wavelet transform, 3D point cloud model containing multiple watermark information was obtained. The algorithm had a high robustness for noise, rotation, translation, scaling, etc., attacks. It was able to embed multiple watermarks, and no collision occurred among multiple watermarks. In conclusion, the algorithm can meet the demand of single-user independent authentication and copyright protection when multi-users share copyright of 3D model.