Digital finance, supported by information technology, has achieved rapid development in recent years. Digital finance essentially relies on the empowerment of “technology” to make the financial system more inclusive. The long brewing cryptocurrency has already entered the implementation phase, which will profoundly change the existing world financial system. Data encryption technology, as a commonly used means of ensuring network information security, has been widely applied in networked financial business systems. To ensure the security and robustness of the digital economy, this word proposes a financial data encryption algorithm based on blockchain technology to reshape the security framework of the digital economy. The article provides a detailed description of the design principle, implementation process, and optimization method of the proposed financial data encryption algorithm based on blockchain technology, and evaluates the performance of the proposed algorithm through simulation testing. The results indicate that the designed encryption algorithm has good encryption and decryption service capabilities, effectively improving encryption efficiency, and has good application value and reference significance.