Abstract: 7075/6061 bimetal composite ingot was prepared by solid/liquid compound method. The influence of the melt temperature of cladding 6061 alloy on the microstructure, composition and hardness of the compound interface was analyzed,and the metallurgical bonding mechanism of the compound interface was discussed. The results show that the shear platform can effectively remove the surface oxide of the inner 7075 alloy semi-solid billet, so that the compound interface is pure and pollution-free. With the increase of cladding melt temperature, the diffusion distances of Cu, Mn and Zn elements at the compound interface gradually increase, and the interface width gradually increases, and the semi-solid microstructure of the inner alloy exhibits an enhanced dendritic evolution trend. The interface mainly realizes efficient metallurgical bonding by synergistic effect of melt convection and atomic diffusion.