Mg-content cored-wire was used to desulphurize and spheroidize ductile iron melt in industrial experiments. The optimal feeding speed and suitable treatment temperature were determined in the experiments. And cored-wire method and pouring method were compared. Conclusions have been drawn that, under these conditions in the experiments, the optimal feeding speed is 15m/min, treatment temperature should be as low as possible, 1400-1450℃ generally; and cored-wire method can act more effective in ductile iron melt desulphurization and spheroid than pouring method. Mg-content cored-wire was used to desulphurize and spheroidize ductile iron melt in industrial experiments. The optimal feeding speed and suitable treatment temperature were determined in the experiments. And cored-wire method and pouring method were compared. Conclusions have been drawn that, under these conditions in the experiments, the optimal feeding speed is 15 m / min, the treatment temperature should be as low as possible, 1400-1450 ° C generally; and cored-wire method can act more effective in ductile iron melt desulphization and spheroid than pouring method .