An international team has produced WE43 magnesium alloy via LPBF, achieving 99.7% relative density and an average grain size of approximately 3 micrometers under optimized parameters of 110 W laser power, 400 mm/s scan speed, and 40 micrometer layer thickness. Under the optimized process, the alloy reaches a tensile strength of 285 MPa, a yield strength of 269 MPa, and an elongation of 10.5%, representing improvements of about 59%, 104%, and 98% respectively over the as-cast condition. This provides a high-performance magnesium alloy forming solution for biodegradable medical implants and lightweight structural components. Value for buyers: magnesium alloy powders are highly reactive and have a narrow processing window; the process window and oxygen content control requirements established in this study offer direct guidance for selecting magnesium powder grades and optimizing process parameters.