A small amount of cross-linked polyethylene (XPE) was added in polyethylene (PE) matrix and then was processed into the pipe by self-designed rotation extrusion system. The experimental results showed that during rotation extrusion of the PE pipe, the polymer melt helically moved forward in an off-axis direction to induce molecular orientation and shish-kebab alignment deviate from the axial direction. However, due to sufficient relaxation of oriented molecules caused by high temperature, numerous spherulites arose in the pure PE pipe. With the addition of XPE, the flow character of PE matrix was tailored so the relaxation was suppressed and the flow effect on the formation of shish kebab was amplified, bringing about denser shish kebabs off the axial direction in the PE pipe. As a result, the PE pipe with excellent endurance to hydrostatic pressure was prepared. The hydrostatic pressure endurance limit of PE pipe was up to 11.7MPa, which was 130% of the standard one.