The work aims to study and analyze the effect of 8% PET bottle packaging with light-blocking oil on the composition and content of flavor substances in sterilized milk, so as to provide data support for prolonging the shelf life of sterilized milk. The light condition of supermarket shelves was simulated. The changes of sensory flavor index, composition and content of characteristic flavor substances of the sterilized milk in different storage periods were analyzed by comparing pure PET bottles and 8% PET bottles with light-blocking oil. The results showed that compared with the sterilized milk in the pure PET bottle, the sterilized milk in the 8% PET bottle with light-blocking oil showed significant differences in the key sensory characteristics (milk aroma, milky smell and off-flavour intensity) and the average value of overall preferenceafter being exposed to light for 3 and 7 days (P < 0.05). The sterilized milk in the light-blocking 8% PET bottle was superior to that in the pure PET bottle in terms of milk aroma and overall preference. Its milky smell and off-flavour intensity was lower than that in pure PET bottle. According to the analysis of characteristic flavor compounds, aldehydes contributed the most to the abnormal flavor of sterilized milk products, while acids, ketones and alcohols contributed less. The light-blocking 8% PET bottle package can effectively slow down the variety and content of aldehydes of sterilized milk products in a storage period of 31 days of light, and can reduce the increase of some acids, ketones and alcohols to a certain extent, so as to reduce the abnormal flavor, improve the preference of products, and extend the shelf life of sterilized milk to a certain extent.