Method for removing iron impurity from magnesium alloy by using Al-B intermediate alloy

The invention discloses a method for removing iron impurity from magnesium alloy by using Al-B intermediate alloy. The Al-B intermediate alloy is added in the magnesium alloy smelting process, and the intermediate alloy supplies an effective element B for removing iron to the melt. The method is suitable for removing the iron impurity from the magnesium alloy containing an alloy element Al; and the method has stable iron removing effect, little impurity introduction during removing the iron, low melt oxidization degree and no harmful gas release.