[目的/意义] 探究社交媒体青年用户健康信息交互行为特征和内在规律，为社交媒体干预用户积极健康行为提供措施和方案。 [方法/过程] 通过收集访谈数据、日志文件、实验视频数据和小红书笔记数据，采用扎根理论和文本挖掘的数据分析方法，对社交媒体青年用户健康信息获取行为特征、健康信息质量评价逻辑和健康信息检索行为模式进行深入分析。同时，基于Engeström活动理论和Kuhlthau信息搜索过程模型，构建社交媒体青年用户健康信息检索行为模式活动模型。 [结果/结论] 社交媒体青年用户获取健康信息的来源呈现入主流与需求驱动的多元选择特点，健康信息内容的关注方式多为推荐触发的需求检索，关注类别为多元核心关注域；社交媒体青年用户健康信息质量评价路径遵循主体认知和客体感知的双路径，健康信息信任度判断依据为内容重合与评论共识的协同检验式信息评估，健康信息的评价方式为“少数服从多数”的群体共识。

[Purpose/Significance] To explore the characteristics and inherent rules of health information interaction behavior among young social media users, and provide measures and solutions for social media intervention in users' positive health behavior. [Method/Process] In this paper, by collecting interview data, log files, experimental video data and Xiaohongshu note data, and adopting the data analysis methods of grounded theory and text mining, an in-depth analysis was conducted on the characteristics of young social media users' health information acquisition behaviors, the logic of health information quality evaluation, and the patterns of health information retrieval behaviors. And based on Engeström's Activity Theory and Kuhlthau's Information Search Process Model, an activity model of the health information retrieval behavior patterns of young social media users was constructed. [Result/Conclusion] The following conclusions were drawn: The sources from which young social media users obtain health information exhibit the characteristics of diversified choices that are mainstream-oriented and demand-driven. The ways in which they pay attention to health information content are mostly demand-based retrievals triggered by recommendations, and the categories of attention fall into multiple core areas of concern. Young social media users' evaluation paths for health information quality follow a dual path of subjective cognition and objective perception. The basis for judging the trustworthiness of health information is a collaborative inspection-style information assessment through the convergence of content and the consensus of comments, and the evaluation method of health information is based on the principle of the minority obeying the majority.