The work aims to increase the adhesive strength of Cu film on sintered NdFeB magnet substrate, improve the solderability of magnet and further prepare the bio-friendly protective film with strong anti-corrosion property. A Cu film with a thickness of about 7 μm was prepared on the NdFeB by magnetron sputtering. The effect of annealing temperature and time on the interfacial structure and adhesive strength of Cu/NdFeB and the magnetic properties of the samples were investigated. The optimized annealed sample was selected to deposit a 2 μm Sn layer by electrodeposition and then an Au flake was soldered to the surface at 280 ℃ to evaluate the solderability. Significant diffusion occurred between the Cu film and the NdFeB substrate when the sample was annealed at 500 ℃ and the diffusion depth and adhesive strength increased as the annealing time extended. The Cu/NdFeB adhesive strength of the sample annealed for 2 h increased to 31.5 MPa from 11.0 MPa, the separation occurred in the subsurface layer of the magnet, and the magnetic properties such as coercivity, remanence and maximum magnetic energy product did not decrease significantly. After Sn was deposited, the soldered Au had good metallurgical bonding with the Cu film and excellent anticorrosion property. For the sample annealed at 700 ℃, the quick diffusion between Cu film and substrate could easily cause the disappearance of Cu film and damage of the NdFeB substrate. The vacuum annealing temperature and time have fundamental effect on the interfacial structure of Cu/NdFeB and suitable annealing can greatly improve the adhesive strength between the magnetron-sputtered Cu film and the sintered NdFeB. At the same time, the magnetic properties have no significant decrease. A high adhesive, long-lasting anti-corrosive and bio-friendly protective film can be prepared on the surface of the heat-treated Cu film by soldering.