The International Cold Chain Trade Platform serves as a trade bridge between overseas suppliers and domestic small and medium-sized customers, providing comprehensive services such as cross-border procurement, supply chain finance and warehousing logistics. However, the current centralized operating model of the trade platform faces trust issues, as data is typically managed and controlled by the platform operator, making it difficult to ensure the authenticity of the data. Blockchain technology, with its inherent tamper-proof and traceable nature, offers a promising solution to address these issues. In this paper, we propose and implement a blockchain-based international cold chain trading platform, which combines cryptographic technologies such as homomorphic encryption and zero-knowledge proofs to ensure data immutability while guaranteeing the authenticity and privacy of platform data. We analyzed the performance and security of the proposed system. The experimental results show that the scheme proposed in this paper is feasible.