Grain safety is of fundamental importance for the whole society. The traditional methods cannot fulfil the requirements of whole grain chain traceability. Also it is hard to combine with the modern technological developments. In view of the two bottlenecks, and based on the analysis of the application and research status of block chain technology in grain industry, the characteristics of block chain technology, such as “decentralization”, “timestamp” and “unchangeable”, and the differences between block-chain traceability mode and traditional traceability mode, this article proposed the application scenarios of block chain technology in the construction of grain traceability system, summarized the development trend of block chain technology innovation, and put forward the key issues that should be paid attention to.