The invention discloses a degradable biomedical Mg-Zn-Zr-Nd alloy material and a preparation method thereof. Magnesium alloy comprises, by mass, 1-3% of Zn, 0.5-1% of Zr, 0.1-1.5% of Nd, and the balance Mg and inevitable impurities. The preparation method comprises the specific steps of raw material smelting, casting forming, homogenizing treatment, hot extrusion and artificial ageing treatment, and the biomedical magnesium alloy bar material meeting the service requirements under the biological fluid environment is obtained. According to the degradable biomedical Mg-Zn-Zr-Nd alloy material and the preparation method thereof, the alloy elements harmless to human bodies are added into the magnesium alloy, the alloy is non-poisonous to the human bodies after being degraded in the human bodies, is excellent in mechanical property, has good mechanical performance and machining performance, is good in corrosion resistance, can be completely degraded in the biological fluid environment and can also ensure the appropriate corrosion rate so that early failure can be avoided. The degradable biomedical Mg-Zn-Zr-Nd alloy material is simple in preparation method, low in production cost and suitable for being made into a cardiovascular stent, a bone nail and other medical materials.