随着新媒体的发展，以微博为代表的社交媒体平台已成为当前舆论传播的主要阵地，信息在社交网络中的传播广度、深度和速度均在快速增长。在社交网络中，公众的情绪暗藏在网民对事件发表的评论和观点之中，情绪传播对事件的发展是一把“双刃剑”，正面情绪的聚集可推动事件向积极的方面发展，而负面情绪的囤积则可能引起极端情绪的宣泄和舆论爆发，造成重大负面影响，从而成为影响社会稳定的不利因素。在全球抗击新冠肺炎疫情的大背景下，网民情绪更加敏感，舆情传播机制更加复杂，舆情爆发的影响力更大，这对我国政府应对突发事件的舆情管理提出了更高的要求。
本研究以“成都确诊女孩”事件为研究对象，以新浪微博为研究平台，通过采集新浪微博上与该事件相关的微博和评论文本，分别从主题和情感两个维度对整个事件发展过程进行历时性分析。研究结果表明，网民对事件的讨论实质上是对事件背后所折射的社会现象的讨论，个人信息泄露和网络暴力就是该事件讨论的焦点问题；官方用户多通过发表情感强烈的正面情感微博促进舆论场情感倾向转变，且效果显著；受群体特征、回音室效应、微博自身的情感倾向和极端程度等因素的共同作用，讨论过程中会出现群体极化现象，且对传播效果和事件热度均会有一定程度的影响。基于以上研究结果，本研究也为相关部门在重大突发公共卫生事件背景下舆情控制的时间节点、运用方式和管理效果方面提供了应对策略。

With the development of new media, social media platforms such as Weibo have become the main field of public opinion communication. The breadth, depth and speed of information dissemination in social networks are all growing rapidly. In a social network, the public’s emotions are hidden in the netizen's comments and opinions about events, and the spread of emotions can be a two-edged sword. The gathered positive emotions can push the event in a better direction, while negative emotions may cause extreme emotional catharsis and the outbreak of public opinion, which may have significant negative effects so that the event will become an adverse factor for society. In the situation that people around the world are fighting against COVID-19, netizens are more sensitive, and the public opinion transmission mechanism is more complex, and the influence of public opinion outbreak is greater, which puts forward higher requirements for the public opinion management of the Chinese government in response to emergencies.
This study takes "Chengdu girl" event as the object of the research and choose sina weibo as the platform in the research. By collecting the comment texts related to this event on sina weibo, diachronic analysis is conducted on the whole event development process from two dimensions of theme and emotion respectively. The results show that the netizens' discussion of the incident is essentially the discussion of the social phenomenon reflected behind the incident, and the personal information leakage and network violence are the main topic of the discussion of this event. The emotional inclination and extreme degree of the microblog and the comment will have a certain influence on the dissemination effect of the microblog. Under normal circumstances, official accounts will publish microblogs with extremely positive emotions to change the sentiment tendency of public opinion, and the effect is significant. Under the joint action of group characteristics, echo chamber effect, micro-blog's own emotional tendency and extreme degree and other factors, group polarization phenomenon will appear in the discussion process, and will influence communication effect and the heat of event discussion. Based on the above research results, this study provides strategies for relevant departments in terms of time nodes, application methods and management effects of public opinion.