"Yunnan Health Code" is a digital epidemic prevention measure launched in Yunnan Province from February 22nd, 20021,which makes the health assessment certificate electronic. Adopt "green code, red code and yellow code" three-color dynamic management. According to the Implementation Opinions on Epidemic Prevention and Control in COVID-19, Yunnan Province (NoticeNo. 10 of Yunnan Provincial Leading Group for Response to Epidemic Situation), all personnel entering Yunnan must declare their personal health status. With the introduction of health code, the whole process of online declaration is realized, and the personal QR code is generated electronically through digital technology.