Abstract: M40 graphite fiber was selected as reinforced material, continuous M40/Al composites whose volume fraction of fiber was 40% and matrix alloys were ZL102, ZL114A, ZL205A and ZL301 alloys respectively were prepared by vacuum gas pressure infiltration, and M40 fibers were extracted using NaOH solution, thus the effects of matrix alloy on the fiber damage and fracture mechanism of continuous M40/Al composites were investigated. The results show that the damages caused by different matrix alloys to M40 fibers are quite different, the tensile strength of fiber extracted from M40/ZL301 composite is the highest, the tensile strength of it is 1 686 MPa, which is about 38.3% of the raw silk tensile strength. While the tensile strength of fiber extracted from M40/ZL102 composite is the lowest, the tensile strength is only 687 MPa, and the roughness of fiber surface is different. There are obvious differences for the fracture mechanisms of different M40/Al composites, when M40/ZL102 and M40/ZL114A composites fracture, there are no fiber pulling out and interfacial debonding, crack passes through fiber transversely, which leads to the failure of composites at low stress. While M40/ZL205A composite shows a small amount of fiber pulling out and slight interfacial debonding. At the same time, M40/ZL301 composite shows a large number of fiber pulling out, crack extends along the interface longitudinally, the interface debonding is obvious, fiber gives full play to its bearing function, and the tensile strength of composite is the highest, which reaches 670.2 MPa.