The invention discloses a preparation method for a deuterium-containing metal film target. The preparation method comprises the following steps: firstly, using high-purity molybdenum or high-purity copper as a substrate material of the deuterium-containing metal film target, and performing surface pretreatment on the substrate material; secondly, mounting and placing the substrate into a physical vapor deposition (PVD) vacuum coating machine, bombarding the surface of the substrate with argon ions, removing an oxide layer on the surface of the substrate by sputtering; thirdly, setting the coating temperature of the substrate, introducing high-purity deuterium gas in a vacuum cavity, starting the coating machine, and directly preparing the deuterium-containing metal film; fourthly, turning off the coating machine, continually introducing deuterium gas into the vacuum cavity, and turning off a deuterium gas flower meter until an appropriate air pressure is reached in the cavity. By adopting the preparation method, the mechanical performance of the deuterium-containing metal film target is improved, the brittleness and occurrence of cracks are controlled effectively, and adhesive force of the target film is enhanced; meanwhile, the thickness of a dead layer on the surface is decreased, the purity of the target film is increased, the neutron yield of a neutron generator is increased, and the service life of the target is prolonged.