Four types of Mg-5Zn porous scaffolds with different pore geometries, including body-centered cubic (BCC), rhombic dodecahedron (RD), primitive (P), and gyroid (G), were designed and fabricated using SLM. Their forming quality, compression mechanical properties, and degradation behavior were investigated. The results indicate the scaffolds fabricated exhibited good dimensional accuracy, and the surface chemical polishing significantly improved the surface quality while reducing forming errors. Compared to the rod structures (BCC, RD), the surface structures (G, P) scaffolds had less powder particle adhesion. For the same design porosity, the G porous scaffold exhibited the best forming quality. The predominant failure mode of scaffolds during compression was a 45° shear fracture. At a porosity of 75%, the compression performance of all scaffolds met the compressive performance requirements of cancellous bone, and BCC and G structures showed relatively better compression performance. Immersed in Hank"s solution for 168 hours, the B-2-75% pore structure scaffold exhibited severe localized corrosion, with fractures in partial pillar connections. In contrast, the G-3-75% pore structure scaffold mainly underwent uniform corrosion, maintaining structural integrity, and the corrosion rate and loss of compressive properties are less than those of the B-2-75% structure. After comparison, the G-pore structure scaffold is preferred.