Abstract: The frequent occurrence of major epidemic public crises all around the world has made a huge test for the China's national emergency management system and the global health security system. The paper aims at the process of joint prevention and control of coronavirus disease (COVID-19) in China and uses grounded theory to make an exploratory analysis by taking the two major military and civilian systems as the core. The study summarizes four main categories including the unified command, arms control, civil defense and risk prediction. Then we builds a model of the military-civilian collaborative governance mechanism under the background of public crisis, and an elemental correlation mechanism from different subject perspectives. It has been found that unified command is the driving mechanism for military-civilian collaborative governance, it plans for crisis management and economic development as a whole from the strategic level. Arms control and civil defense are the motivation mechanism for military-civilian collaborative governance, through joint action to protect governance needs and fulfill social responsibilities. Risk prediction is the feedback mechanism for military-civilian collaborative governance, it takes risk assessment as the basis for decision-making of the governance subjects. The conclusion provides theoretical guidance and practical inspiration for the improvement of China's national major epidemic management system and the global epidemic situation.