Purified magnesium sacrificial anode was prepared by using short flow process of smelting crud magnesium directly.The filter was set in the reduction pot to reduce the impurity content in the magnesium silico-thermic process.Low pressure transferring method and layered heating furnace refining method were adopted to purify the magnesium melt

and the melt purifying mechanism was described.It is shown that the filter can capture directly the oxide in the impurities to decrease the content of Ni

Si

Fe.Meanwhile

temperature gradient was established to make Al crystallization ahead of Mg to decrease Al content in the crude magnesium during the magnesium silico-thermic process.Additionally

the inclusions in the melt were decreased sharply by using low pressure transferring method and layered heating furnace refining method.The electro-chemical properties test results reveal that both current efficiency and open potential performance are better than those of the magnesium sacrificial anode standard.