SixDomainChain (SDChain) is a decentralized public blockchain ecosystem that integrates international standards of IoT Six-Domain Model and references architecture standards for distributed blockchain. Fully considering the technical characteristics of IoT and the development needs of business ecosystem, SDChain is optimized based on existing blockchain technology with digital asset issuance, user credit and identity management, P2P communication, encryption algorithm, consensus algorithm, smart contract, cross-chain contract mode, market consensus-based incentives, decentralized DApp and rapid access to business.