Abstract: The outbreak of COVID-19 warned the importance of building effective early warning mechanisms for new major infectious diseases. In the existing early warning system of infectious diseases in China, it is difficult to balance the timeliness and certainty when reporting infectious diseases. Based on the hospital data, this paper analyzes the cases, medical resources, pathological features and their relationship, proposes an infectious disease risk measurement algorithm based on complex network modeling, and constructs an infectious disease risk early warning and data sharing system based on blockchain technology. The proposed system realizes the safe storage and sharing of data through the blockchain technology, conducts distributed global model training through federal learning, and combines smart contracts and doctor's experience to realize timely and accurate early warning of infectious disease risk. The nodes in blockchain can automatically report the early warning after reaching the distributed consensus, further improving the early warning and reporting process.

Key words: Infectious diseases, COVID-19, Epidemic warning, Complex network, Blockchain, Data sharing