Selective Laser Melting (SLM) and Selective Electron Beam Melting (SEBM) were used to fabricate pure tungsten. The microstructure and mechanical properties of pure tungsten were compared under different process parameters. The crack initiation location and formation mechanism were analyzed by SEM and EBSD. The results show that the crack generation of pure tungsten printing process can be effectively reduced by adjusting the process parameters in SLM and SEBM process. The relative density and hardness of pure tungsten samples are proportional to the energy density input by SLM and SEBM. Compared with SLM, SEBMed pure tungsten has lower temperature gradient, less thermal stress accumulation and fewer cracks. There were many cracks in SLMed samples, and that mostly existed in the lap areas. Cracks in SLMed and SEBMed samples were distributed along grain boundaries, most of which were initiated at high-angle grain boundaries.