The invention provides a biomedical magnesium alloy provided high corrosion resistance and capable of being uniformly degraded. The degradable magnesium alloy comprises strontium (Sr). The magnesium alloy is an Mg-Zn-Mn system. 1.0-1.5% (in mass fraction) of strontium (Sr) is added. An element Sr is added into an Mg-Zn-Mn alloy, so that biocompatibility of the magnesium alloy is further improved on the basis of improving mechanical property, and corrosion type of the alloy is changed into uniform corrosion from local corrosion. The alloy system disclosed by the invention is a compact structure, and Sr exists in the form of an Mg17Sr2 phase. The corrosion product is a Ca/P compound close to a human bone component, and has very good biocompatibility.