Abstract: Urban public health emergencies management is one of the most important aspects of urban public management, modernization of urban governance system and governance capacity. Evidence based governance (EBG) is a kind of governance mode under the concept of evidence-based decision-making, in which multiple governance subjects form research evidence based on rigorous and scientific methods, and make scientific decisions by using the evidence. Evidence-based governance method can make every decision have evidence to follow, and realize the system innovation of urban public health prevention and control work. Based on the analysis of the existing governance system and its problems of public health emergencies in China, A theoretical framework of evidence-based governance was constructed. In the perspective of the governance evidence, public value and leadership, the process of public health emergencies evidence-based governance includes four stages: evidence-based prevention and control period, evidence-based early warning period, evidence-based control period and post-mortem evidence-based reconstruction period. Around the production, dissemination and application of evidence of evidence-based governance, the evidence-based governance mechanism of public health emergencies was summarized. An empirical study of system dynamics approach on the process of production, transmission and use of evidence during the process of epidemic prevention was taken by the early governance process of COVID-19 pneumonia epidemic, the results show that the quality of early evidence of COVID-19 epidemic was overestimated, and both the public value orientation and leadership of decision makers needed to be improved. Thus, ensuring the scientific of evidence and realizing the coordination among the three subsystems of evidence production, evidence dissemination and evidence application were the basis to promote the effective operation of evidence-based governance system and realize good governance. Finally, some policy recommendations such as to build an evidence platform for optimizing evidence-based governance in public health emergencies was put forward. For example, the production of evidence needed the collaborative development of multi departments, institutions, interdisciplinary and fields. The dissemination of evidence should be open, transparent, timely and effective, and all participants can share effective evidence in time. It is necessary to strengthen the cultivation of evidence-based concept of urban decision-makers, and improve the collaborative mechanism between departments and regions.

Key words: public health emergencies; evidence-based governance; the best evidence; COVID-19 pneumonia epidemic