In twin-roll strip casting process, the temperature variation of casting roll can result in roll thermal stress and fatigue. It not only affects the thermal deformation of casting roll and the generation of the roll surface cracks significantly, but also influences the surface quality, shape and profile of the produced strip, and the service life of the casting roll. In this paper, a 3D coupling thermal-flow finite element modelling has been conducted. For twin-roll casting of stainless steel, the influences of the casting speed and liquid level in molten pool on the temperature field of casting roll have been simulated and discussed. The developed model is very helpful in optimising the processing parameters and the design of casting roll during twin-roll thin strip casting.