随着数字经济的不断发展和进步，数据要素流通交易效率及安全性将成为制约数据经济发展的关键。提出一种基于区块链跨链技术的数据交易机制，该机制以区块链生态为基础，以数据价值安全传递为核心，构建数据资产价值评估模型，旨在推动数据安全交换，推动数据生态建设。首先，通过交易联盟及见证人机制解决区块链数据验证、资产评估、数据确权等问题，缩短了交易的时间；其次，通过应用密码、多方安全计算、默克尔SPV（simplified payment verification）路径验证等技术的融合应用保证了交易的隐私性、真实性和完整性，实现了链上链下数据安全交换；再次，运用基于B-S（Black-Scholes）期权定价模型为数据资产价值评估提供了科学指导；同时，中继链为数据交易的各个环节进行记录，保证了整个交易过程的透明性和不可否认性；最后，在实验环境中验证了系统的运行性能。该机制的设计为数据资产价值安全交换提供了新的思路。

With the continuous development and progress of the digital economy, the efficiency and security of data element circulation and transactions have been made key factors for developing the data economy. A data transaction mechanism based on blockchain cross chain technology was proposed, which was based on the blockchain ecosystem, and was centered on the secure transmission of data value. It constructed a data asset value evaluation model, aiming to promote data security exchange and data ecosystem construction. Firstly, by transaction alliances and witness mechanisms, the blockchain data verification, asset valuation, and data ownership confirmation were resolved and the transaction time was reduced. Secondly, the integration of technologies such as cryptography, multi-party secure computation, and Merkel simplified payment verification (SPV) path verification, the privacy, authenticity, and integrity of data transactions was ensured, secure exchange of on chain and off chain data was achieved. Once again, the application of the Black-Scholes(B-S) option pricing model provided scientific guidance for evaluating the value of data assets. At the same time, the relay chain recorded various stages of data transactions, the transparency and non repudiation of the entire transaction process was ensured. Finally, the operational performance of the system was validated in the experimental environment. The design of this mechanism provides new ideas for the secure exchange of data asset value.