Objective: In order to solve the problem that traditional traceability system cannot guarantee the reliability and integrity of data, and strengthen the protection and monitoring of cold chain food. Methods: Based on the trustworthiness and traceability of blockchain technology, the Hunan Provincial Market Supervision and Administration Bureau had built a traceability system for the Hunan Cold Chain. Hunan Cold Chain adopt a storage method that could read and write separation, and used a cache system to improve the efficiency of the blockchain system to read and write status data. Results: Thereby achieving data sharing in the traceability link of the imported cold chain in Hunan Province through traceability links, traceability codes, product management and information. Conclusion: The on-chain anti-tampering function realizes a credible closed-loop cold chain food physical defense traceability system to ensure food safety.