[目的/意义]突发公共卫生事件中信息疫情（Infodemic）的爆发向全球公共健康信息传播提出了巨大挑战。信息过载是全媒体时代信息疫情的主要表现形式，突发公共卫生事件中信息过载引发的用户信息规避行为是健康信息学研究的重要议题。[方法/过程]本文以新型冠状病毒引发的肺炎疾病（COVID-19）为例，旨在探寻突发公共卫生事件中信息过载如何通过认知和心理因素影响用户的信息规避行为。基于信息行为理论与压力应对理论，提出研究假设并构建理论模型，利用问卷调查方法和结构方程模型进行实证分析。[结果/结论]研究结果表明，信息过载会使用户产生负面情绪并夸大自身感染新冠肺炎的可能性，从而导致用户对有关信息产生防御心理，减少与信息的接触行为。研究结论有助于进一步了解信息过载对用户健康信息行为的影响，为突发公共卫生事件中信息疫情的应对提供启示。

[Purpose/significance] The outbreak of infodemic in public health emergencies is a big challenge for public health communication and patient education. Information overload, a state that users are overwhelmed by too much information or mis- /dis-information, is a primary manifestation of infodemic in the era of global information flow. [Method/process] This paper used the novel coronavirus disease (COVID-19) as a case to illustrate how information overload can affect users' information avoidance behavior from cognitive and psychological perspectives in public health emergencies. Based on information behavior theory and stress coping theory, this paper proposed a theoretical model and several related hypotheses. The study adopted the survey approach and structural equation modeling method for data collection and analysis. [Result/conclusion] The findings showed that information overload is associated with users’negative emotions and perceived susceptibility of the COVID-19, which further resulted in a defensive motivation and reduction of exposure to health information. The study may enrich the literature of both information overload and health information behavior, and yield practical implications for coping with infodemic in public health emergencies.