With the development of global economic integration, cross-border trade has become an important driving force for global economic development. However, it is facing issues such as data security, information silos, and information asymmetry. Based on this, this study proposes a blockchain-based scheme for data sharing and access control in cross-border trade. The scheme uses a collaborative storage mechanism of blockchain and inter planetary file system (IPFS) to effectively reduce the storage load of blockchain. In addition, a dual key regression model combined with time dimension is adopted to encrypt and store data, as well as assign access permissions by setting different time periods, which limits the unnecessary access of data users outside a certain time span. Finally, corresponding smart contracts are designed to achieve efficient management of the entire life cycle flow of data, improving sharing efficiency. The experimental results show that the proposed scheme can achieve secure data sharing in cross-border trade and fine-grained access control for users.