Abstract: Electron beam welding of Cu/Al/Cu lamellar metal composites was studied. Surficial formation of weld, microstructure and mechanical properties of welded joints were analyzed. The results showed that Cu/Al/Cu lamellar metal composite could be effectively connected by electron beam welding. Weld width of different metal layers was obviously different, Al layer had the largest width, and a large amount of Al layer metal entered Cu layer weld at the top and bottom. IMCs layer appeared at the interface of weld and base metal of each layer. Al layer was mainly Al2Cu, while Cu layer was mainly AlCu and Al2Cu. A large amount of massive Al2Cu generated in the center of weld and evenly distributed in the eutectic matrix composed of α-Al and Al2Cu. Tensile strength of welded joints was 44 MPa, fracture showed obvious brittle fracture characteristics, and tensile fracture located in the center of weld with the highest microhardness.Highlights: (1) Cu/Al/Cu lamellar metal composites were used instead of pure Cu in the industrial field.(2) Electron beam welding technology was used to weld Cu/Al/Cu sandwich lamellar metal composites.