Objectives <p>To explore the impact of acceptance commitment therapy(ACT) to treatment on the mental health of elderly breast cancer patients.</p> Methods <p>Sixty elderly breast cancer patients admitted to a cancer hospital were selected and divided into a control group (<i>n</i>=30) and an intervention group (<i>n</i>=30). The control group received conventional interventions, The intervention group received an additional ACT. Psychological status, quality of life, sense of meaning in life of the two groups were observed and compared.</p> Results <p>After intervention, the self-rating anxiety scale (SAS) and self-rating depression scale (SDS) scores of the intervention group were lower than those of the control group (<i>p</i>&lt;0.001,&#xa0;<i>p</i>&lt;0.001). In terms of sense of meaning in life, the intervention group scored significantly higher than the control group at post-intervention (<i>p</i>&lt;0.001); Additionally, in terms of quality of life, the scores of the intervention group after the intervention were significantly higher than those of the control group (<i>p</i>&lt;0.001).</p> Conclusion <p>The effect of ACT in elderly patients with breast cancer can effectively improve the psychological state, quality of life and sense of meaning in life of patients, and the application of this therapy can be further promoted in the future.</p>