Focusing on emergency management, we re-examine the implication and governance direction of online public opinion in emergencies, aiming to support both the effective control of online public opinion risks and rational communication of emergency risks through public opinion governance. Firstly, we systematically review the analytical frameworks and governance logics of existing online public opinion research, and clearly classify them into crisis management paradigm and risk communication paradigm; Secondly, we reshape the cognitive landscape of online public opinion in emergencies, and discuss the implication and essence of online public opinion in emergencies from the perspective of risk construction, and describe the positive and negative mechanisms of online public opinion in terms of risk perception and social motivation; Finally, we propose an analytical framework of online public opinion based on the subject and the ontology of public opinion to support the governance of online public opinion in emergencies, with risk management and emergency response management as the goal orientation. This study broke the crisis management paradigm of traditional online public opinion research, reshaped the cognitive picture of online public opinion in emergencies, constructed an analytical framework of online public opinion in emergencies and therefore can provide new perspectives and reference bases for emergency management of emergencies and online public opinion governance.