The invention relates to a metal wire used in a clinic cardiac sternal closure surgery and a manufacturing method thereof. The metal wire is made of a titanium alloy Ti-6Al-7Nb wire subjected to bioactive coating treatment. Tests show that the Ti-6Al-7Nb wire has excellent mechanical properties similar to those of a stainless steel wire and excellent compatibility similar to human tissues and avoids damages to human bodies. After the further surface bioactive coating treatment of the metal wire, a ceramic oxide film with a plurality of pits are formed on the surface of the wire, so the compatibility of the meal wire with the human tissues is further improved. The Ti-6Al-7Nb wire can be implanted into a human body permanently and can meet requirements on the metal wires used in the clinic cardiac sternal closure surgeries.