Extrusion screw that is used on market of present extrusion molding catapult is divided by single-axle extrusion screw and multi-axles extrusion screw. Simulation technique of screw that is used in extrusion molding has become so far various. Consist of that analyze third dimension model and that analyze two-dimension model but most Analysis that display dynamic characteristic of screw inside of heat and flow in detail was not until present. Transfer of polymer site that typical single-axle extrusion screw that is analysis target of this treatise is mixed in most melting state is good, but has some controversial points. First melting transfer of balance that is not done difficult. Second melting causes effect that weaken mechanical special quality of screw by power excessive last month if heighten the screw speed to increase amount of done balance. Third Screw dynamic characteristic symptoms by thermal expansion that happen in screw of heater is fallen.