Abstract: Purpose/Significance Public information collection and access to emergency events are broadened by social media’s openness, and the public’s call for participation in social governance enables public behavior data assist decision-making. Meanwhile, evaluating the value of large and mixed information can help identify key message and critical people, and make decisions based on group wisdom more scientific; secondly, member weights have a significant impact on group decision-making, and an objective and scientific weighting method enables more reasonable decision-making results. Design/Methodology To tackle the issues of complex environment and lower public participation in large group emergency decision-making, a method is proposed from the perspective of public-assisted decision-making based on individual fuzzy expressions to measure the information value and ordinary information to integrate the inter-group distance, thus methods are proposed for determining individual weights based on cognitive features and expression ability, and adjusting alternatives under collective wisdom. Conclusions/Findings COVID-19 case is carried out as a scenario, and the feasibility and superiority of methods are verified through comparative analysis with existing literature at different levels to provide theoretical and methodological support for public-expert collaborative decision-making problems.