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.