Abstract: Taking polyethylene pipes as the research object, the oxidation induction time of polyethylene pipes was tested using a differential scanning calorimeter, and the effects of sampling location and natural climate exposure time on the oxidation induction time test results were studied. The results show that without the influence of natural climate, the oxidation induction time of the middle, inner, and outer surfaces of polyethylene pipes decreased in sequence. The oxidation induction time in the middle of polyethylene pipes varied little with the natural climate. After 90 days of natural climate exposure on the outer surface and 150 days of natural climate exposure on the inner surface, the oxidation induction time of the sample significantly shortened, and the shortening time on the outer surface was longer. After 240 days of natural climate action, the oxidation induction time along the thickness direction of the polyethylene pipe at a distance of more than 9 mm from the outer surface or more than 6 mm from the inner surface was closer to that of the original pipe.