According to the multi-region features in alloy solidifying process,numerical simulation of rapid solidification following laser remelting is performed by using a one -phase continuum model based on the conservation of total mass, momentum and energy. The release of latent heat, the energy flux leaving the surface by radiation and natural convecton into the atmosphere are included. The finite difference method is used to solve the equations. The flow field and temperature distribution within the liquid pool during rapid solidifying process are studied for lCrl8Ni9Ti stainless steel. Results show that the moving speed of iiquidus line is greater than that of the solidus line during solidifying process, and at the end of solidification of the molten pool, there is a period of time during which the mushy region and solid region are coexist.