Objective: To analyze the clinical effect of detailed management nursing in breast cancer patients treated with trastuzumab. Methods: A total of 80 breast cancer patients admitted to Changzhou Cancer Hospital between January 2017 and December 2019 were selected for this study. They were randomly divided into two groups, a control group and an experimental group, each with 40 patients. Both groups were given trastuzumab. The control group was given routine care during the treatment, and the experimental group was given detailed management care during the treatment. The psychological state score, nursing quality score and nursing satisfaction were compared between the two groups before and after nursing. Results: After nursing, the experimental group was significantly different from the control group in depression and anxiety scores (P<0.05). The scores of patients in the experimental group on basic nursing, nursing skills, health education, and nursing service attitudes were significantly higher than those in the control group, with a statistically significant difference (P<0.05). The nursing satisfaction of the experimental group reached 97.50%, which was significantly higher than that of the control group (82.50%), with a statistically significant difference (P<0.05). Conclusion: Detailed nursing management is definitely effective in breast cancer patients treated with trastuzumab and worthy of clinical promotion.