[Purpose/significance] The increasing complexity, interactivity, professionalism, and impact of public health emergencies have brought grand challenges for traditional emergency management systems. This paper aims to provide an innovative and multi-layered perspective for public health crisis management based on the power of the crowd. [Method/process] This paper targets at the outbreak of COVID-19 and endeavors to revisit the wisdom of crowds in public health emergencies. Specifically, the study reviews the current status of crisis crowdsourcing and health-related citizen science projects, and proposes a conceptual framework for the construction of citizen science platforms for public health emergencies. [Result/conclusion] We identify three problems in the application of citizen science for public health emergency management: emphasizing response but ignoring prevention; emphasizing participation but ignoring cooperation; emphasizing contribution but ignoring co-production. Firstly, we clarify the essence of citizen science in the public health domain. Secondly, we discuss the construction of citizen science platform in the public health emergencies domain from three aspects, "making" and "using", fundamental framework, and influence. Overall, the study can shed light on the construction of national emergency management systems, enhancing the capacity for social prevention and control, and improving public health literacy.