The long manufacturing process, difficult coordinated regulation of structural properties and interface bonding ability aresome of the difficulties that restrict the rapid development of lightweight composite plate forming and manufacturing for along time. In order to solve the above problems, this paper proposes adding hard plate to roll Al/Mg/Al composite plates. The thickness of Mg/Al is 10:1, and the hard-plate rolling process experiments were carried out by designing five groupsof different temperatures. The influence of magnesium plate microstructure evolution on the interface bonding ability andmechanical behavior of composite plates is mainly studied. Under the same conditions, the matrix microstructure changesgreatly from 200 to 350 °C. At 350 °C, the microstructure of Mg plate in ND is uniform without shear bands and twins. Itsrecrystallization ratio is 31.77%, which played a role in weakening the texture and reducing its anisotropy. Interestingly,in the process of three-point bending, the non-basal plane slip and the basal plane slip start simultaneously, the maximumbending strength of the composite plate reaches 504 MPa, and the interface was well bonded without obvious bending fatiguephenomenon. The tear test showed that the tear load reaches 0.42 kN, and the elastic elongation stage of Al is longer than thetear propagation stage, and the interface bonding was uniform. The hard plate rolling process provides scientific guidancefor the forming and preparation of composite plates.