Bimetal composite materials having multifunction and more performance are one of the research focuses, at present. And then, the 7075/6061 cladding bimetal composite ingots with “semi-solid microstructure / dendrite microstructure” distribution characteristic were prepared by the solid / liquid metals compound casting. Interfacial morphology and mechanical properties of the ingots with different melt temperatures were analyzed and tested. At last, the interface bonding mechanism of the ingot was discussed. The results show that the 7075/6061 cladding bimetal composite ingot has a advantageous microstructure distribution and morphology, and has the best compressive strength, while the parameters are the outside melt temperature 760 ℃, the billet pre-temperature 300 ℃, holding time 40 min and air cooling. With the increasing of the outside melt temperature, the near-spheroidal α-Al solid particles of the semi-solid billets of the inner layer 7075 alloy are more coarsening and more non-spherical, the remelted area of the semi-solid billet at the bonding interface also increase. Otherwise, as the outside melt temperature increasing, an evolution rule of the semi-solid microstructures nearby the bonding interface is occurred following: near-spheroidal solid particles merging and growing, non-spherical crystal, dendritic crystal. During the compression mechanical property test at ambient temperature, the samples fracture along 45° angle direction to axis, and not along the bonding interface.