This work investigated the refinement of Al3Ni phase in Ni-7050 composite, which was prepared by the melting reaction with two different components, 5% and 10% Ni added in 7050 aluminium alloy. Hardness tests, metallographic observation, SEM and DSC were used to analyze the structures and performances. The results show that the hardness of the two composites was obviously increased to 1918 and 2364 MPa after T6 aging. Fracture analysis shows that the fracture mechanism was mainly Al3Ni brittle fracture and interfaces debond. Experiments were designed to investigate the influences of annealing/rolling treatment on structures and properties of the composites. The results indicated: (1) Long time annealing treatment could induce refinement and spheroidization of the Al3Ni phase. With the annealing time prolonged, the hardness first increased and then decreased. (2) After multi-step hot/cold rolling, the microscopic structure of composites showed that the size of Al3Ni phase changed progressively, Al3Ni phase was smashed and transformed from original long slab to nearly isometric particles