<p>Wet packs of loaned surgical instruments have always been a challenge for the Central Sterile Supply Department. Compared to other factors affecting pressure steam sterilization, loading is full of variables in practice. Based on the Product Family Categorization Theory, this project scientifically evaluates the steam penetration resistance level of each kit of loaned surgical instruments according to their different attributes to guide the sterilization staff to standardize the loading. By optimizing the loading method, the sterilization staff can quickly determine the most difficult to sterilize the loaned surgical instruments package in each batch, and select the best sterilization procedure according to its level, reducing their subjective judgment, and making the selection of sterilization procedures more standardized. That is to reduce the generation of wet packs, but also to ensure the safety of the use of patient equipment. However, due to manpower and time constraints, this study was only conducted in loaned surgical instruments and was a single-center study, and the sample size can be further expanded in the future to provide a basis for further improvement of the theory.</p>