：文章结合相关媒介理论，选择此次新冠肺炎疫情中的典型案例，分析了疫情中公众接触的主要媒介类型和信息来源有哪些，不同媒介及信源的接触如何影响着公众的媒介信任和社会信任，媒介传播又如何影响着人们的健康防护行为和国家宏观层面的疫情防控举措。研究发现：专业新闻媒体、公众社交媒体、聚合媒体、医学媒体和政务媒体是公众在疫情中接触的主要媒介类型；主流新闻媒体在疫情中彰显了卓越的专业素质，在独立真实、报道及时、贴近民生、社会关怀等方面表现优秀；聚合媒体、医学媒体等也充分彰显了及时纠错、贴近民生、关怀社会、无私独立等可信度特质，增强了社会信任；社交媒体上假消息泛滥、数据不严谨、以及新闻媒体的信息公开制度不够完善等负面传播问题，影响了公众对媒介和社会的信任；医学媒体在疫情中极大推动着社会公众的健康防护行为，新闻媒体对疫情期间的议程设置、舆论引导和国家宏观层面的防控布局有着重要影响。

Based on classic media theories and typical case studies, this paper analyzed the main media types and information sources in COVID-19 infections, and the impacts on media trust and social trust, as well as the effects on public health prevention and national epidemic control. It found that news media, social media, aggregated media, medical media, and government media were the five main media types in this pandemic. News media performed well on professionalism, timeliness, closeness to public, and social concern. Aggregated media and medical media also deserved public trust on error recovery, closeness to public, unselfishness, etc. The fake news on social media, inconsistent data, and information disclosure lag impaired public trust on media. Medical media promoted the health preventive behavior of the public. News media greatly influenced the agenda setting, public opinion, and national epidemic control in the COVID-19.