Credit Safe Application Chain (CSAC), a public blockchain for real industry applications. CSAC is a blockchain technology similar to Bitcoin and Ethereum. It is mainly aimed at the ecosystem of finance, insurance, port clearing business in UK, credit traceability, credit forecasting, credit anti-fraud and credit history. Through this ecosystem, we can build a decentralized risk management and transaction management platform spanning multiple ecological fields, and create technological applications in the area of credit traceability, credit certification, credit tracking, credit cost reduction and so on.