The invention discloses a metal composite material and a fused deposition 3D printing method of a bone implant of the metal composite material. The metal composite material comprises a nickel-titanium alloy and double-component composite bone cement, and the mass ratio of the nickel-titanium alloy to the double-component composite bone cement is 10-16:8-14. The 3D printing method includes the steps that firstly, an STL model file is input; secondly, the nickel-titanium alloy and powder of the double-component composite bone cement are subjected to ball milling mixing, and a discharged mixture is added into a powder charging barrel; thirdly, liquid of the double-component composite bone cement is added into a liquid charging barrel; and fourthly, technological parameters of a 3D printer are adjusted, the discharged material of the powder charging barrel and a discharged material of the liquid charging barrel are input into a printing nozzle after being evenly mixed, printing forming is conducted, and sintering is conducted after curing. The binding force of the composite bone cement and the nickel-titanium alloy can be improved, the composite bone cement is prevented from being disengaged, the biological activity of the nickel-titanium alloy is improved, and biocompatibility between the implant of the metal composite material and the human tissue is improved.