Abstract: Blockchain technology is a distributed ledger technology widely used in all walks of life in recent years. Due to its high efficiency, continuity, immutability and other good characteristics, blockchain is highly praised by relevant people. Nowadays, with the development of food production technology, people pay more and more attention to food safety. The main problem is that the sources of food raw materials are more extensive, the managers lack the information of food raw materials, and the employees have more information of raw materials. This kind of information asymmetry increases the difficulty of traceability of food raw materials after the completion of food production. In addition, the storage of large quantities of information also bothers the managers of the food industry. This paper mainly explores the methods of building traceability system by using blockchain in various food and drug industries, and explores other promoting roles of blockchain technology in food safety, hoping to provide some guidance for the future application of blockchain technology in food safety.