Abstract: A method for preparing Mg-RE alloys with high strength and ductility using selective laser melting (SLM) additive manufacturing technology includes the following steps of: A. preparing Mg-RE-(Zn)—Zr pre-alloyed spherical powder by gas atomization; B. molding the Mg-RE-(Zn)—Zr pre-alloyed spherical powder using SLM to obtain the Mg-RE alloys with high strength and ductility; and C. conducting heat treatment on the Mg-RE alloys prepared in step B: solid solution+aging treatment or only aging treatment The method adjusts and controls microstructure and mechanical properties of the alloys by adjusting and controlling process parameters of SLM (laser power, scanning speed, hatch spacing, spot diameter, layer thickness, interlayer rotation angle, substrate preheating temperature, partition width and overlapping area width) and process parameters of subsequent heat treatment (temperature and time) to prepare the Mg-RE-(Zn)—Zr alloys with high strength and ductility using SLM process for the first time.