In the quickly developing landscape of Web3.0, ensuring the security and integrity of digital documents has become paramount. This abstract introduces a groundbreaking solution, "Web3.0 Document Security: Leveraging Blockchain Technology," which harnesses the power of blockchain to revolutionize document transmission and protection. This innovative system leverages the inherent characteristics of blockchain, such as immutability, transparency, and decentralization, to develop a secured and sealed environment for the exchange of digital documents. By utilizing smart contracts, cryptographic hashing, and decentralized storage, this application guarantees the confidentiality, integrity, and authenticity of documents in an interconnected Web3.0 world. This paper provides an overview of the key features, benefits, and implications of adopting a decentralized application as the foundation for secure document transmission in the era of Web3.0 . Keywords— Documents, Data Security, Data Integrity, Secure Transmission, Cryptography, Blockchain, Cloud Technology, Web3