As an important part of intelligent packaging system, intelligent indicator labels can monitor, sense and record the physical, chemical and biological changes of fresh food during the circulation process in real time, and has become one of the important means to ensure food safety and reduce food loss. Intelligent indicator labels can not only directly monitor the metabolites of fresh food (such as carbon dioxide, ethylene, etc.), but also indirectly reflect the freshness and safety of fresh food from the external environmental status (such as oxygen, temperature, etc.). Among them, the direct factor intelligent indicator labels are mainly categorized into freshness-indicating and ripeness-indicating types, while the indirect factor intelligent indicator labels are mainly categorized into temperature-indicating and leakage-indicating types. On this basis, by combining with information technology such as radio frequency identification (RFID), intelligent indicator labels can also realize remote transmission and visualization of quality information of fresh food, which is conducive to the full-chain supervision of food safety in China.