Objective To observe the effects of phyllanthifructus spray intervention on salivary flow rate, salivary pH, and degree of oral dryness in nasopharyngeal carcinoma patients with radiation-induced xerostomia. Methods A total of 93 nasopharyngeal carcinoma patients with radiation-induced xerostomia who met the inclusion and exclusion criteria in the radiotherapy department were selected and randomized into a conventional group, a cold water group, and a phyllanthifructus group using a random number table, with 31 patients in each group. The conventional group received routine treatment and care, on the basis of the conventional group, the cold water group additionally received cold water oral spray, and the phyllanthifructus group received phyllanthifructus solution oral spray with a concentration ratio of 1:5, which lasted 2 weeks. The salivary flow rate, salivary pH, and degree of oral dryness before and 2 weeks after the intervention were compared among the three groups. Results After the intervention, there were statistically significant differences in salivary flow rate, salivary pH, and degree of oral dryness among the three groups (all P<0.05). In pairwise comparisons, the salivary flow rate, salivary pH, and degree of oral dryness in the phyllanthifructus group were significantly better than those in the other two groups (all P<0.05). Conclusion Phyllanthifructus spray intervention in nasopharyngeal carcinoma patients with radiation-induced xerostomia can promote salivary gland secretion, accelerate the repair of damaged salivary glands, and enhance the oral pH, thereby alleviate the severity of oral dryness in nasopharyngeal carcinoma patients undergoing radiotherapy.