The FTIR infrared spectroscopy method was used to analyze the changes of the PP group and the modified PP at the time of aging(the most important is the infrared absorption peak of the carbonyl compound).The change of the PP carbonyl index was also known.We can understand the process of light and oxygen aging and the mechanism of light stabilizer on PP.After accelerated aging,it was found that the carbonyl index of pure PP increased with the increasing of aging time.The carbonyl index of modified PP after adding HALS was relatively small,and the change range was small,and the anti-aging effect was obvious. The FTIR infrared spectroscopy method was used to analyze the changes of the PP group and the modified PP at the time of aging (the most important is the infrared absorption peak of the carbonyl compound.) The change of the PP carbonyl index was also known. We can understand the process of light and oxygen aging and the mechanism of light stabilizer on PP. After accelerated aging, it was found that the carbonyl index of pure PP increased with the increasing of aging time. The carbonyl index of modified PP after adding HALS was relatively small, and the change range was small, and the anti-aging effect was obvious.