Polymer pipes are widely used to transport fluids due to the excellent combination properties. However, in convention extrusion, the molecular chains orient along the axial direction so the cracks easily propagate parallel to the axis. Inspired by structure and performance of bamboo that the axial aligned fibers result in easy axial but difficult transverse cracking, we developed a novel rotation extrusion equipment to independently adjust rotation of mandrel and die as well as the simultaneous cooling of inner and outer walls during the process of polymer pipe, forming the reinforcing phases off axial direction and greatly improving performances of the pipes. This paper further simulated the flow behavior and temperature distribution during rotation extrusion of polymer pipe. The results showed that rotation extrusion obviously decreased the extrusion pressure and more importantly, with the superposition of the axial flow and the hoop drag flow caused by the mandrel or die rotation, the polymer melt moved helically forward, and the velocity and direction were closely related to extrusion rate, rotation speed, rotation mode and the position in the annular gap. Accordingly, the alignment of reinforcing phases in polymer pipes can be tailored via rotation extrusion. Moreover, the temperature across polymer pipe under three cooling modes, i.e., sole inner cooling, sole outer cooling and double cooling of inner and outer walls were also computed, indicating the temperature distribution could be controlled by the cooling media’s temperature, type and flowing rate, and the temperature of melts could be quickly cooled down via the double cooling mode, favorable to retention of the reinforcing phase off the axial. Obviously, the simulation results will provide a guide to adjust processing parameters to prepare excellent-performance polymer pipes via rotation extrusion. This work was supported by the National Natural Science Foundation of China (51127003 and 51421061).