OBJECTIVE To provide reference for safe use of bevacizumab in tumor patient. METHODS Retrospective analysis was performed for a case of tracheomediastinal fistula caused by bevacizumab after radiotherapy in which clinical pharmacist participated. Retrieved from PubMed ，Elsevier Science Direct ，Springer Link ，Wiley Oline Library ，CNKI and Wanfang database ，the cases of respiratory fistula caused by bevacizumab were collected ，and the causes of respiratory fistula were analyzed. RESULTS & CONCLUSIONS Referring to relevant literatures ，combined with the formation position of fistula and considering its correlation with the use time of bevacizumab ，considering that it may be bevacizumab related tracheomediastinal fistula，clinical pharmacists recommended that patients stopped bevacizumab and underwent stent implantation. The patient refused to implant stent for personal reasons ，but the tracheomediastinal fistula improved 3 months after drug withdrawal. Combined with the data of 16 patients with respiratory fistula caused by bevacizumab ，it could be inferred that the use of bevacizumab on the basis of radiotherapy may be the cause of tracheomediastinal fistula ；the mechanism may be related to bevacizumab inhibiting angiogenesis and affecting wound healing. This suggests that for patients who have received radiotherapy ，clinical pharmacists should strengthen medication monitoring and medication education when using bevacizumab ；clinical pharmacists should not only pay attention to the common adverse reactions such as hypertension and bleeding caused by the drug ，but also pay attention to rare but life-threatening adverse reactions such as respiratory fistula ，so as to ensure the safety of drug use.