The process of vertical twin-roll casting including pouring, solidifying, roiling and cooling can be accomplished In a very short time. Some Important process parameters In roll casting that are difficult to be obtained experimentally may be acquired by employing numerical simulation. In this paper, a numerical simulation has been conducted based on a 20 finite element model of vertical twin-roil ab1p casting coupling temperature, flow, and thermal stress. The Influences of key process parameters Including submerged nozzle depth and nozzle spray angle have been studied. The distribution of thermal stress was obtained and Its effect on the cracks In the casting strip was discussed.