30%。 The flow, temperature, pressure fields and viscous heating distribution in a triple screw extruder were studied by using computational fluid dynamics (CFD) method. The effects of screw rotational speeds, numbers of screw thread, pressure difference and flow rate on productivity ratio and power consumption were employed with considering temperature by pressure build-up and viscous dissipation. At the same time, the characteristics of power consumption of triple screw extruder were compared with those of traditional twin screw extruder. The results show that with the increase of screw rotation speed, pressure difference and flow rate, the power consumption of triple screw extruder increases and the productivity ratio of it decreases. With the increase of numbers of screw thread, the power consumption of triple screw extruder increases. By comparing, it is found that the productivity ratio of triple screw extruder increases 30% than that of twin screw extruder.