Based on a new metal forming simulation package,MSC Superforge,the metal flow inside the die in the course of spread extrusion has been simulated and analyzed.The influences of the die parameters including the inflow entry width,outflow exit width,cavity height,basic working land length and flowing hole position on the metal flow have been studied.As a result,the data from that numerical simulation have a significant contribution to the optimization of the design of extrusion dies.