Due to the existing technical conditions, it is impossible to accurately locate people at risk of big data to counties, cities and streets. Once you find that your health code does not match the risk level, you can consult or appeal to the local community or county (city, district) centers for disease control and prevention according to the principle of territorial management. The local community or county (city, district) centers for disease control and prevention will conduct epidemiological investigation, and according to the investigation results and personal commitment, transcode or decode the health codes of people who do not meet the risk level or have completed health prevention measures.