The roll bonding process of the sandwich sheet is a preferable production method to manufacture multilayer sheets and it needs clear investigation because some industrial parts cannot fulfill all of the requirements by single-layer material. In this study, a theoretical model of roll bonding has been reviewed and hot sandwich rolling processes with different plate thickness and flow stress were numerically investigated. The contact pressure-dependent bonding properties in the deformation zone were defined. Then, the liner thickness and reduction ratio are important parameters to determine the total deformation zone. When the thickness of the liner becomes large, unbonded length of deformation can be a serious problem and at the same time, the good bonding strength can be found at a higher reduction ratio of the thinner liner.