The invention relates to a PPR plastic pipe with a self-repairing function and a preparation method thereof and belongs to the field of PPR pipe preparation. According to the preparation method of thePPR plastic pipe with the self-repairing function, the preparation method of the PPR plastic pipe includes the following steps that a, polyacrylic acid and poly allylamine hydrochloride are mixed uniformly into a mixed solution, the interlayer inner wall of an inner pipe body and an outer pipe body of the PPR plastic pipe are uniformly coated with the mixed solution, film forming is performed through thermal crosslinking, and the coated PPR pipe is obtained; and b, self-repairing micro capsules and light-blocking filler are mixed, an interlayer of the inner pipe body and the outer pipe body of the coated PPR pipe is filled with the mixed self-repairing micro capsules and light-blocking filler, and the PPR plastic pipe with the self-repairing function is prepared. After cracking happens tothe prepared the PPR plastic pipe, cracks can be fast repaired, pipe blasting is prevented, and the service life of the pipe is prolonged.