The satellite internet, characterized by global coverage and high-speed connections, enables rapid data transmission, irrespective of geographical constraints or limitations of traditional communication networks. This facilitates effective and dependable data trading. However, the absence of mutual trust between trading parties leads to complications such as security, compliance, trustworthiness, fairness, and privacy protection. To address these challenges, this work proposes a cross-domain data trading scheme that leverages satellite internet, blockchain technology, and decentralized digital identity technology for conducting identity verification while maintaining privacy. By introducing verifiable random functions, efficient verification of multi-source data is achieved, enhancing the security of the scheme. In addition, an arbitration mechanism, which utilizes on-chain smart contracts and off-chain identity providers, is devised. A comprehensive analysis of the scheme’s security and performance is undertaken, with the evaluation illustrating the scheme’s effectiveness in managing multi-source data trading.