Abstract: With a cooling plate mounted in the traditional mold, the composite aluminum alloy ingot for making brazing sheet was prepared in lab by the direct-chill (DC) semi-continuous casting process, and such a process was investigated involving mainly temperature field distribution near the contact interface between two different aluminum alloys during DC casting, macro-morphology, microstructure and distributions of both components and hardness of the composite ingot. The results showed that the semi-solid layer with a certain thickness is formed under the action of cooling plate in the vicinity of the contact interface, thus ensuring the successful implementation of casting the composite ingot, where the two different aluminum alloys are well bonded together metallurgically. It was found that the distributions of components and hardness of the two different aluminum alloys in the composite ingot are in corresponding relation.