Objective: To observe clinical efficacy of Lanzhou Formula (兰州方) with Bingpeng Powder (冰硼散) mouthwash in preventing and treating radiation-induced oral mucositis. Methods: A total of 200 patients with malignant tumors in the head and neck who received radiotherapy in our hospital from April 2018 to April 2020 were selected as research objects, and they were randomly divided into the study group and control group. The control group was given radiotherapy combined with mouthwash, which consisted of 500 mL of normal saline, 125 mg of vitamin B12, 400000 U of gentamicin and 1 g of lidocaine. The study group was given radiotherapy combined with Lanzhou Formula with Bingpeng Powder mouthwash. Incidences of radiation-induced oral mucositis, chewing and swallowing functions, and Karnofsky (KPS) scores were compared between the 2 groups. Results: At the end of the radiotherapy, there was no Grade 4 radiation-induced oral mucositis in the 2 groups. Compared with the control group, the radiation-induced oral mucositis in the study group basically belonged to Grade 1 and Grade 2, with a lower incidence of Grade 3 (P<0.05). At the end of the radiotherapy, the chewing and swallowing functions in the 2 groups were decreased, but patients with 2-point chewing and swallowing functions in the study group were more than those in the control group, and patients with the 3-point were less than those in the control group (P<0.05). At the end of the radiotherapy, the KPS scores were decreased, but those in the study group were higher than those in the control group (P<0.05). Conclusion: During radiotherapy for patients with malignant tumors in the head and neck, Lanzhou Formula with Bingpeng Powder mouthwash can decrease the severity of radiation-induced oral mucositis, protect chewing and swallowing functions of patients to a certain extent, and improve the general condition of patients. It is worthy of clinical application and promotion.