Abstract: COVID-19 epidemic occurs in the era of big data, in addition to the tension between public interests and personal information rights, the requirement for joint prevention and control in the big data era further increases the risk of personal information being violated. From the perspective of COVID-19 prevention and control, this paper analyzes three principles that should be followed in protection of personal information in public health events: absolute public benefit, proportionality and due process, and proposes specific measures for personal information protection in public health incidents. On this basis, the paper tries to construct a personal information protection system in public health emergency, that is: to specify a normalized path of protection, to establish a protection institution and to confirm relief channels after personal information is infringed.