In twin-roll strip casting process, the casting speed has a significant influence on the metal flow and temperature distribution in the molten pool, which will affect the stability of this process and the quality of the produced products. Based on a 3D coupled thermal-flow analysis, a combination of the experimental results for twin-roll strip casting of stainless steel, heat equilibrium calculation and simulation results was conducted, and the boundary conditions of the heat exchange between the rolls and molten pool has been treated effectively. The effect of the casting speed on the flow and temperature in the molten pool was given. Simulation result is in agreement with the measured value.