The invention relates to an Mg-Zn-Sr-Ca-Zr medicinal bone nail and a preparation method thereof, wherein the Mg-Zn-Sr-Ca-Zr medicinal bone nail comprises the composition and content: 2%-4% of Zn, 1%-2% of Sr, 0.5%-0.7% of Ca, 0.3%-0.5% of Zr, and the balance magnesium and other impurities unable to remove. The medical bone nail is prepared and molded by powder metallurgy and thread rolling process and comprises a screw head, a hexagonal wrench and a screw rod. The Mg-Zn-Sr-Ca-Zr medical bone nail reduces the addition of rare earth elements, so the bone nail has better biological compatibility and corrosion resistance than an original magnesium alloy based on mechanical performance ensuring requirements, and has the advantages of simple structure, and convenient manufacture.