Abstract: This paper overviewed research progresses in numerical simulation of extrusion die application in the recent decade. Research findings in the numerical simulation of extrusion die, gas-assisted extrusion and co-extrusion were introduced in detail. The complex flow channel structure was considered as a difficulty for the design of profile dies, and a significant progress in the design of complex dies was achieved with the aid of Polyflow software. Compared with traditional extrusion, gasassisted extrusion and gas-assisted co-extrusion had more advantages for reducing die-swell ratio. Simulation of gas-assisted extrusion only provided a theoretical evaluation, and however, it was still in shortage of enough applications in large-scale industrialization. Polyflow software could approximately predict the location of interfaces for extrudates during simple die extrusion.