Compassion fatigue is an important problem affecting the physical and mental health of nurses and the quality of nursing work. To understand the status quo of compassion fatigue and humanistic care ability of ICU nurses and analyze the correlation between them is very important for ensuring the physical and mental health of nurses and improving the quality of nursing work. In this paper, from February 2023 to April 2023, a total of 197 ICU nurses from 9 Class ⅲ Grade A hospitals in Xi'an were selected as the research objects by the convenient sampling method. The general information questionnaire, Compassion Fatigue Scale for Medical Staff, and Humanistic Care Ability Evaluation Scale were used to investigate them. The results showed that the score of compassion fatigue of ICU nurses was (103.80±17.99), which was at a medium level. The score of humanistic care ability was (191.24±20.75), which was at a low level. The total score of compassion fatigue was negatively correlated with the total score of humanistic care ability (r=-0.568, P<0.01), and the total score of compassion fatigue was negatively correlated with the dimensions of cognition, courage, and patience (r=-0.325, -0.509, and -0.184, respectively, all P<0.01). Humanistic care ability scores and loss of mental tension, enthusiasm, behavior, negative, emotional indifference, ability to doubt, was found to be inversely associated with the loss of morale dimension (r, respectively 0.357, 0.390, 0.428, 0.262, 0.539, 0.477, P<0.01). This study highlights the interaction between compassion fatigue and humanistic care ability in ICU nurses. Nursing managers should pay attention to and take effective measures to reduce the level of compassion fatigue of ICU nurses in time to improve their humanistic care ability, and should also strengthen the humanistic care education and training of ICU nurses to improve their humanistic care ability to reduce the level of compassion fatigue.