The work aims to metallize the surface of the ferrite electromagnetic core by vacuum coating technology, and comprehensively analyze the structure and performance of the metal composite film to provide a theoretical basis for engineering application. Multi-cavity integrated magnetron sputtering equipment was used to deposit Cr, Ni and Ag on the surface of ferrite magnets as the metal composite film on ferrite. The surface and cross-section morphology of the composite film were characterized by scanning electron microscopy. The surface roughness of the composite film was measured by atomic force microscopy. The adhesion of the composite film was tested by the cross-cut method. The peel strength of the composite film was tested by stamping test. The tensile strength of the composite film was tested by tensile test. The solder resistance of the composite film was tested by immersion tin test. The thickness of Cr/Ni/Ag composite films was 420, 4200 and 550 nm respectively. Cr layer and Ni layer had obvious columnar crystals. The interface between layers was clear without obvious pores. The Ag layer was tightly combined with Ni layer. The surface roughness of composite film was 13 nm, adhesion was 0B, bonding force was 30 N and tensile strength was 49 MPa. After tin immersion for 18 s at 450 ℃, the metal film had no desoldering or exposure. The Cr(420 nm)/Ni(4200 nm)/Ag(550 nm) composite metallized film prepared by magnetron sputtering technology has compact and uniform structure and excellent comprehensive performance, which meets the technical requirements of ferrite inductor surface metallized film.