Abstract:3D printing technology can fabricate complex structures to achieve personalized customization of bone implants. When in-situ alloying is employed to prepare uncommon alloys, the step of preparing pre-alloyed powder can be omitted, thereby reducing costs. In this study, block and porous Fe-30Mn alloys were prepared by PBF-LB in-situ alloying and studied the effects of different printing parameters on the performance of specimens. Insufficient laser energy input during printing leads to inhomogeneous mixing of iron and manganese, which degrades the material’s properties. Excessive energy input can cause manganese to vaporize, yielding a composition that deviates from the target. With optimized laser parameters, block specimens exhibiting a uniform Fe-Mn distribution can be obtained with an ultimate tensile strength of 644.67 MPa, an elongation of 21.61%, and a corrosion rate of 0.042 mm/year in simulated body fluid. Moreover, the resulting porous scaffold shows 49.84% porosity, a 0.2% offset yield strength of 66.11 MPa, a compressive strength at 20% strain of 170.76 MPa, and an elastic modulus of 6.41 GPa. The results of indirect toxicity tests and cell adhesion tests showed that the materials had good biocompatibility. Taken together, these results indicate that the Fe–30Mn alloy produced via PBF-LB in-situ alloying holds promise for biodegradable human bone implants.