The invention relates to a mould for simultaneously cooling the inner and the outer pipe walls of a plastic pipe during molding, belonging to the technical field of accessory devices of a plastic pipe production line. The mould comprises a mould body, a core mould, a core mould base, a mouth mould, a neck mould and the like. The mould body is internally provided with the core mould and the core mould seat, and the core mould is provided with a strainer sleeve or a spiral body; and the left end of the mould body is provided with the neck mould, the right end of the mould body is provided with the core mould and the mouth mould, a blowing guide pipe is arranged in the centers of the core mould and the core mould base, the left side of the blowing guide pipe is provided with a fan, a fan frequency converter and an industrial control computer. When the mould for simultaneously cooling the inner and the outer pipe walls of the plastic pipe during molding is molded, melt flows through a shunt runner and are superposed layer by layer, and thus, not only are the melt and a lateral incipientfusion phenomenon improved through an elliptic structure of a distribution barrier, but also the inner pipe wall and the outer pipe wall are synchronously cooled by using the fan to blow natural wind onto the inner wall of a plastic pipe blank via the blowing guide pipe. Therefore, the problem that the outer wall of the plastic pipe always has internal stress and incipientfusion when water cooling is adopted in the prior art is solved, and the stress cracking resistance and the shock resistance of the plastic pipe are improved.