The work aims to deposit Mg-Gd-Y-Zr alloy on surface of AZ91D magnesium alloy and analyze the micros-tructure evolution and mechanical properties of cladding layer. DC PTIG welding was used to convey the welding wires of Mg-Gd-Y-Zr alloy to the AZ91D magnesium alloy molten pool at different average current to prepare cladding layer. The microstructure of cladding layers was analyzed by metallographic microscope, scanning electron microscope, energy dispersive spectroscopy and X ray diffraction pattern. The hardness and tribological properties were characterized by Vikers microhardness and reciprocating wear tester. The main phases of cladding layer were composed of α-Mg, Mg24(Gd,Y)5, and Al2(Gd,Y). The difference in distribution and morphology of Mg24(Gd,Y)5 lead to the layered morphology. With the increase of average current, the central grain size of cladding layer kept unchanged at first and then increased rapidly, and the Al2(Gd,Y) phase changed from fine dispersed particles to agglomerated distribution and the morphology of Mg24(Gd,Y)5 located at the grain boundary transformed from a continuous network to disconnected and fragmentized islands and then spheroidal particles. The hardness of cladding layer increased slightly and then decreased sharply with the increase of average current, and the maximum hardness reached 90.8HV. The weight loss rate of cladding layer during wear test at the current of 110 A was lower than that of substrate. The cladding layer containing Gd and Y rare earth elements with better wear resistance than AZ91D substrate can be prepared successfully on the surface of AZ91D magnesium alloy by DC-PTIG. The morphology and distribution of the Al2(Gd,Y) can be determined by the dilution ratio of cladding layers.