A three-dimensional finite element simulation model of fluid field including front-box and droplike-shape-spacer nozzle of aluminum roll-casting has been developed to provide analyzing distribution of velocity and temperature of outlet of nozzle. The computation was performed by using coupled fluid-thermal FEM simulation of FLOTRAN module in ANSYS 6.0. The boundary conditions of the roll-casting model of fluid and thermal fields, were loaded on front-box and nozzle. Based on the data from postprocessing function of ANSYS, the strict result analysis was conducted by MATLAB. Results based on the allowable inhomogeneity of velocity and temperature of outlet show the most possible broken regions of outlet could be predicted in the case of speed increasing of the drawing-sheet and thickness reducing of the aluminium sheet. Droplike-shape-spacer nozzle in this example only applied to normal speed, and must be optimized to be appropriate in high roll cast speed.