Objective To explore the application effect of a nursing management mode based on Swiss cheese model in safe medication for chemotherapy patients in daytime wards. Methods The study included chemotherapy patients in the Department of Day Care Ward of Tianjin Medical University Cancer Institute & Hospital between February and March 2023 (before improvement) and between June and July 2023 (after improvement). Before the improvement, a conventional nursing management mode was adopted, and after the improvement, a nursing management mode based on the Swiss cheese model was adopted. The medication safety ability of nurses, adverse drug events, and patients’ satisfaction of nursing before and after improvement were compared. Results Finally 150 patients were included before and after improvement, respectively. There was no statistically significant difference in age, gender, educational level, per capita monthly household income, tumor staging, and disease diagnosis between the two groups of patients (P>0.05). The total score of patients’ satisfaction of nursing after improvement was higher than before improvement (22.99±1.52 vs. 20.45±2.14, P<0.05), but there was no statistically significant difference in the dimensions of treatment environment and service attitude (P>0.05). There was no change in the nursing staff before and after the improvement, and a total of 34 nurses were included in the Department of Day Care Ward. The total score of the nurses’ medication safety ability was higher than before improvement [162.00 (160.75, 166.25) vs. 136.00 (135.00, 138.00), P<0.05], but there was no statistically significant difference in the dimensions of improving medication safety issues, multidisciplinary collaboration ability, and nursing professional responsibility (P>0.05). The incidences of adverse events during daytime chemotherapy after improvement were lower than before improvement (P<0.05). Conclusion The nursing management mode based on Swiss cheese model can improve the safety medication ability of nurses, reduce adverse events of chemotherapy medication in daytime wards, and improve patient satisfaction, which can be promoted in clinical practice.