目的 探讨机械通气患者家属替代决策困境体验，为提升替代决策者的决策质量 和满意度提供参考。 方法 2020年5月-2020年10月，对长沙市某三级甲等医院ICU所收治机械通气患者的替代决策家属进行半结构访谈，以Colaizzi现象学分析法对访谈资料进行编码、分类、解释及分析。 结果 分析得出以下三大主题院决策行为类型多样、决策内心活动复杂、决策挑战多维化。 结论 需关注和识别机械通气患者家属作为替代决策者的困境和需求，增进医护人员与替代决策者之间的沟通和信任，优化家属参与医疗决策的心理支持及应对策略，提升替代决策者的决策能力和满意度。

Objective To explore the experiences of surrogate decision-making dilemma among mechanically ventilated patients’ family members，and to provide a guidance for improving the decision quality and satisfaction of proxy decision-makers. Methods From May 2020 to October 2020，semi-structured interviews were conducted with family surrogate decision-makers of mechanically ventilated patients in ICU of a tertiary care hospital in Hunan Province. The interview data were coded，categorized，interpreted，and analyzed by Colaizzi phenomenological analysis. Results The following three themes are obtained from the analysis: diverse types of decision-making behavior，com- plex inner activities of decision-making, multi-dimensional decision-making challenges. Conclusion It is necessary to pay attention to and identify the dilemmas and needs of family surrogate decision-makers for mechanically venti- lated patients，enhance communication and trust between medical staff and surrogate decision-makers，and optimize psychological support and coping strategies for family surrogate decision-makers，so as to improve the decision-mak- ing ability and satisfaction of surrogate decision-makers.