Aiming at the problems of single supervision, centralized rights, and privacy leakage in the supervision process of the existing agricultural product traceability system, a blockchain hierarchical supervision model for wheat supply chain was designed and implemented after in-depth research on the characteristics of the whole business process of the wheat milling industry. In traditional traceability system of agricultural products, once there were problems such as product quality and privacy disclosure, it was difficult to precisely locate the responsibility, timely recall the products and prevent the information disclosure in time. Thus regulation was an indispensable part of the supply chain to ensure the integrity and legality of data. The above problems would be addressed to examine the application case of the Inner Mongolia’s Zhaofeng Hetao Noodle Industry. Based on the multi-chain architecture of blockchain, the hierarchical supervision model of wheat authority control was designed and realized through Hyperledger Fabric of the alliance chain. The enterprise traceability data was open and transparent, and the privacy data was encrypted then uploaded to the blockchain. Privacy keys were encrypted and transmitted through the Ciphertext-Policy Attribute-Based Encryptionto achieve privacy protection and fine-grained control of data for enterprises. The traceability code was used as the traceability key value, which was stored in the blockchain together with the regulatory results.After proliferation test, the average change rate of the cipher text was 95.5% by changing any bit of the key to be encrypted while the control policy remained unchanged and the average change rate of the private key was 75.5% by changing the access policy while keeping the key unchanged, which possessed high security and confusion. After performance testing, the average query latency of the hierarchical supervision model designed was 6.67ms for public traceability data, 34.45ms for privacy data decryption, and 37.78ms for data supervision, which can meet the actual application requirements of wheat. Theoretical analysis and experiments showed that the hierarchical supervision model proposed can achieve privacy protection, hierarchical authorized supervision, and real-time supervision of the whole process. On the premise of ensuring the independent operation of each module, it can strengthen information interconnection which had strong practicality.