Objective To explore the effect of ultrasound therapy on dysphagia caused by radiotherapy for nasopharyngeal carcinoma. Methods From February to December, 2017, 60 patients with radiation-induced dysphagia for nasopharyngeal carcinoma were randomly divided into control group (n = 30) and treatment group (n = 30). All the patients accepted routine rehabilitation and balloon dilatation. The treatment group received ultrasound therapy, and the control group received placebo ultrasound. They were evaluated with Kubota Drinking Water Test (KDWT) and Videofluoroscopic Swallowing Study (VFSS), and the interincisor distance were measured to determine the clinical effect, before and six weeks after treatment. Results The score of KDWT (Z = -2.253, P < 0.05) and the pass time in VFSS (t > 2.4265, P < 0.05) improved more in the treatment group than in the control group after treatment, as well as the incidence of effect (Z = -4.113, P < 0.001). Conclusion Ultrasound therapy can further improve the function of swallowing based on the balloon dilatation.