Sichuan steamed rice retort is a traditional tool for steaming food, usually made of bamboo. In order to increase the heat resistance and durability of retort, some retort will be treated with bamboo charcoal. Bamboo charcoal is a kind of bamboo carbonized at high temperature, which has the characteristics of moisture absorption, deodorization and antibacterial. When making retort, bamboo charcoal and bamboo are processed together to make the retort surface appear black. This black retort pouch is not only beautiful in appearance, but also can improve the service life of retort pouch and the taste of steamed rice.