The work aims to introduce a certain proportion of cyclic olefin copolymer (COC) material into the outer layer of polypropylene (PP) five-layer co-extrusion hoses, and study its effect on the barrier performance of the hoses. The melting behavior of the COC/PP blends of different proportions was analyzed. The oxygen and water resistance properties, tensile strength, bending modulus, notched impact strength of the blends were also tested. With the increase of COC, the permeability of oxygen and water vapor decreased. When the COC dosage was 20 wt%, the oxygen permeability was as low as 3.3 cm3/(d.m)2, and the water vapor permeability was 0.6 g/(d.m)2. At the meantime, the other properties also achieved a good balance. It is concluded that the presence of COC can effectively improve the water and oxygen resistance performance of the PP five-layer co-extrusion hoses.