In a centrifugal casting process,the fluid flow and temperature filed eventually determine the quality and characteristics of final high speed steel composite roll.A three dimensional solidification model coupling of heat transfer and flow of molten metal in horizontal centrifugal casting on high speed steel composite roll was established,it can calculate the distribution of temperature filed and flow filed under gravity and centrifugal force by using CFD software FLUENT.The reason for free surface which is eccentrically distributed is also discussed.The analysis results can contribute to the understanding of flow filed in centrifugal casting process and centrifugal casting technology in optimized design.