Introduce the simulation technology of the latest of extrusion machine for the polymer processing. FAN (Flow Analysis Network) method is possible to analyze the extruder entire region based on the two dimensional calculation. The latest technology of FAN method is applied to three dimensional field by 2D-3D coupling technique. FEM and FVM analysis apply to prediction of detail screw mixing behavior by three dimensional calculation. Particle method is newly technology for polymer processing (high viscosity non-newtonian fluid). Recently, DEM-MPS coupling analyze technique is developed and it shows qualitative prediction for polymer plasticization in the twin screw extruder.