The present invention provides a degradable corrosion-resistant high strength and ductility magnesium alloy for biomedical use and the preparation method therefor. With regard to a total weight of the magnesium alloy of 100%, the composition of components of the magnesium alloy comprises: 1.0 to 4.5% of Nd, 0.2 to 2.0% of Zn, 0 to 1.0% of Ca, 0 to 1.0% of Zr, and balance of Mg. The magnesium alloy is prepared by producing a magnesium alloy ingot by means of vacuum semi-continuous casting and according to the components and weight percentage thereof followed by solid solution treatment and extrusion. The degradable corrosion-resistant high strength and ductility magnesium alloy for biomedical use provided by the present invention has the advantages of being non-toxic and fully degradable, good corrosion resistance as well as high strength and ductility etc., and can be used for preparing a vascular stent.