The effects of GdCl_3 in flux on the loss of Gd,microstructure,mechanical properties,and corrosion resistance of Mg-Gd-Y-Zr(GW103K) scraps were investigated by ICE XRD,SEM and EDS.The results show that the loss of Gd in the alloy decreases with increasing GdCl_3 content in the flux,and the mechanism of GdCl_3 suppressing the loss of Gd was analyzed by thermodynamic theory.The optimal average mechanical properties could be obtained when the GdCl_3 content in the flux was 5% (mass fraction).Compared with the alloy only treated by JDMJ flux,theσ_b andσ_s of GW103K alloy were improved from 160.91 MPa and 133.88 MPa to 224.96 MPa and 157.91 MPa by 39.8%and 17.95%,respectively.Immersion test shows the corrosion rate of Mg-Gd-Y-Zr alloy refined by JDMJ+5.0%GdCl3 flux was decreased dramatically from 0.762 mg/(cm^2·d) to 0.437 mg/(cm^2·d)by 42.7%.GdCl_3 has no effect on the fracture pattern of GW103K alloy.