Abstract: In order to avoid generating extremely short edges on the artificial boundaries while applying the 2D Parallel Constrained Delaunay Meshing（PCDM） algorithm directly into 3D conditions, this paper proposes a 3D PCDM algorithm based on master-slave model. First of all, the domain is decomposed into several sub-domains and the mesh consistency is maintained by exchanging data on the artificial boundaries. Then the master and slave sub-domains are chosen for each artificial boundary. The master sub-domains send the generated boundary meshes and the slave ones receive them simultaneously. Finally, cupidity arithmetic is used to balance the communication load of the sub-domains, which leads to the improvement of efficiency. The experimental results show that the proposed algorithm can generate large-scale tetrahedral elements with conforming mesh along artificial boundaries in parallel, and can also provide a good parallel efficiency with the guarantee of mesh quality.