In order to investigate the effect of vacuum degree on the interface microstructure and mechanical properties of stainless steel clad plate, series of 316L/Q235 clad plates were successfully fabricated by hot rolling with different vacuum degrees of 10(5) Pa, 400 Pa, 10 Pa, 10(-1) Pa and 10(-2) Pa. Interestingly, with the increase of vacuum degree, the interface oxides distribution changed from continuous wall/film to dispersed refined particles, and the thicknesses of martensite layer, decarburized layer and carburized layer were gradually increased. Meanwhile, the interface bonding strength of clad plates can be effectively enhanced by improving the vacuum degree. Due to thin decarburized and carburized layers, the stainless steel clad plate with a low vacuum degree of 10(5) Pa reveals superior yield strength and ultimate strength, while a low fracture elongation was obtained due to severe interface delamination. However, the stainless steel clad plate with a high vacuum degree can obtain a superior tensile ductility, which is attributed to the strong interface and localized necking delaying effect.