To explore the preventive effect of Banxia Baizhu Tianma Decoction（半夏白术天麻汤）combined with ear acupoint stimulation on postoperative nausea and vomiting（PONV）in breast surgery.

One hundred and thirty patients with breast cancer who were admitted to Longhua Hospital affiliated to Shanghai University of Traditional Chinese Medicine from January 2023 to March 2024 were enrolled for the research. They were divided into the observation group（Banxia Baizhu Tianma Decoction combined with ear acupoint stimulation）and the control group（ear acupoint stimulation alone）through a random number table，65 cases in each group. The preoperative baseline data，surgery related data，postoperative incidences of PONV，headache and headache and visual analogue scale（VAS）score as well as blood levels of tumor necrosis factor-α（TNF-α），interleukin-6（IL-6）and 5-hydroxytryptamine（5-HT）at 30 minutes before and 24 hours after surgery were compared between observation group and control group.

There were no statistically significant differences in preoperative baseline data，surgical related data and the blood levels of TNF-α，IL-6 and 5-HT at 30 minutes before surgery between the observation group and the control group（P>0.05）. The total incidence of PONV and the incidence of PONV above grade 2 in the observation group were significantly lower than those in the control group（P<0.05）. The blood levels of TNF-α，IL-6 and 5-HT in two groups at 24 hours after surgery were significantly higher than those at 30 minutes before surgery，and the blood levels of TNF-α，IL-6 and 5-HT in the observation group were significantly lower than those in the control group at the same time（P<0.05）. There were no significant differences between the observation group and the control group in the incidence of dizziness，headache or VAS score after breast cancer surgery（P>0.05）.

Banxia Baizhu Tianma Decoction combined with ear acupoint stimulation could effectively reduce the risk of PONV in patients with breast cancer after surgery，and the preventive effect was better than that of ear acupoint stimulation alone，which is worthy of promoting.