A356/6061 bimetallic specimens were prepared by liquid-solid compound casting. The effects of various casting conditions on the interfacial microstructure and mechanical properties of the bimetallic specimens were studied. Results demonstrate that a combination of chemical zinc deposition and electroplating can create a dense protective layer on the surface of the 6061 aluminum bar, achieving complete metallurgical bonding at the bimetallic interface. The interfacial microstructure is primarily characterized by equiaxed grain formation, with eutectic silicon distributed along the grain boundaries. Notably, the thickness of the zinc plating layer does not significantly influence the microstructure of the interface transition layer. Pouring temperature is critical for establishing metallurgical bonding at the bimetallic interface, with the thickness of the transition layer increasing as the pouring temperature rises. The hardness of the bimetallic composite interface falls between the hardness values of the two constituent materials. While the thickness of the galvanized layer has a minimal effect on interfacial shear strength, there is a slight decrease in shear strength with increasing pouring temperature, with a maximum value recorded at 68 MPa.