Car Data Chain is a new ecological car service platform developed based on blockchain technology. It integrates blockchain technology into transaction scenarios, circulation scenarios, and service scenarios in the automotive industry. A series of information are stored on the chain. Blockchain technology establishes a trust system based on machines rather than conventions. The decentralized system composed of technologies such as smart contracts and distributed databases makes the auto service industry more transparent, authoritative and fair. On the Car Data Chain platform, auto manufacturers, points of sale, auto trading markets, auto finance companies, car leasing companies, insurance companies, and banks can all join the platform to form a comprehensive auto service system and provide users with high-quality solutions .