Absorbable metal intramedullary nail and preparation method thereof

The invention discloses an absorbable metal intramedullary nail and a preparation method thereof, which belong to the technical field of medical appliance. The intramedullary nail is a straight nail or a radian nail and is characterized in that the intramedullary nail comprises the follow components in percentage by mass: 0.01 to 10 percent of Zn, 0.01 to 5 percent of Ca, 0.001 to 5 percent of Fe, 0.01 to 5 percent of Mn and the balance of Mg; and the outer surface of the intramedullary nail is provided with a compound coating. The elastic modulus and the density of the intramedullary nail are close to those of a human body, which avoids or reduces stress shielding effect and promotes fracture union; and simultaneously, the intramedullary nail has higher intensity so as to make up the shortage of a degradable polymeric material. The intramedullary nail can be absorbed continuously in the human body and can generate a phosphate layer of Ca and Mg during the absorption and degradation, which contributes to bone conduction. The degradation rate can be regulated effectively by changing components and a structure of alloy, and components and a structure of a coated coating.