Abstract: Hot-rolled bimetallic composite plates are widely used because of their excellent properties. In the recent years, the enhancement of the combined performance of hot-rolled bimetallic composite plates has gained the attention of the industry. The molecular dynamics simulations were employed to assess the high-temperature combined performance of 316L/Q345R bimetallic plate systematically. The hot-compression process of the 316L/Q345R system was simulated on its atom structure model. The potential functions of the embedded-atom method were employed to describe the interaction between Fe, Cr, and Ni. The effects of temperature and compressive strain rate on the mechanism of the hot-compression deformation and the thickness of the diffusion layer were analyzed. The influence of adding a metal layer on the interface bonding performance was also discussed. The results show that increasing the temperature up to the composite melting point leads to the formation of a thicker diffusion layer at the bimetallic interface. However, an increase in the strain rate reduces the thickness of the diffusion layer, because the diffusion and compression time of the atoms shortens as the strain rate increases. The influence of the addition of a Ni or a Cr layer on the combined performance was investigated. The thickness of the diffusion layer of the bimetallic interface was increased by 134.5% when a lattice thickness Ni layer was added in the bimetallic interface; however, the addition of a Cr layer did not improve the combined performance. This study provides new insight into the factors that directly influence the performance of hot-rolled bimetallic composite plates.