Abstract: With the increasing demand for lightweight equipment in the fields of aerospace, transportation, Mg-rare earth (Mg-RE) alloys have shown broad application prospects due to their excellent specific strength and specific rigidity, considerable creep resistance, and high temperature mechanical properties. The welding process can reduce the difficulty of fabricating large and complex Mg-RE structural parts, which is beneficial to their further application in related key fields. This article focuses on the characteristics of Mg-RE alloys and introduces their properties and applications. The effect mechanism of rare earth elements on the weldability of magnesium alloys has been discussed, and the welding processes applicable to Mg-RE alloys in the world in recent years has also been reviewed. Furthermore, the effects of pre-weld and post-weld heat treatments on the formation properties, microstructure, properties, and welding defects of the joints has been summarized. Finally, the research direction of the welding process of Mg-RE alloys is prospected.