Nearly two-thirds of China’s population uses rice as their staple food. The safety of the rice supply chain is directly related to the health of the people and the prosperity of the country. Rice supply chain has the characteristics of long life cycle, complex participation roles of main links, many harmful species, multidimensional and multi-source heterogeneity of information and so on. The realization of dynamic supervision of rice supply chain is conducive to the guarantee and traceability of rice quality and safety. Driven by blockchain smart contract, a dynamic model suitable for the information flow characteristics of rice supply chain was constructed, and contractual implementation and prototype verification were carried out. Firstly, based on the analysis and classification of rice supply chain supervision information, a dynamic supervision model framework of rice supply chain was constructed based on blockchain smart contract. Secondly, under the logical framework of the regulatory model, six types of smart contracts, including initialization smart contract, data calling smart contract, model verification smart contract, smart contract for data transmission, contribution evaluation smart contracts, and credit assessment smart contract, were custom-designed. And the smooth operation of the model was analyzed. Finally, based on the dynamic supervision model and smart contract, the rice supply chain supervision prototype system was designed and developed. And simulation analysis and case verification were carried out. The results showed that the dynamic supervision model and prototype system constructed can solve the whole process real-time management of rice supply chain business information, hazard information and personnel information, and realize the dynamic and credible supervision of rice supply chain in the whole life cycle at the information level. The research presented a generation of information technology in the efficient coordination and resource sharing of food supply chain, and provided ideas for the digital transformation of the grain industry.