Objective To explore the clinical effect of ultrasonic cleaner combined with tongue brush and scraping in the treatment of halitosis in elderly. Methods A total of 160 elderly patients with halitosis, aged 60 to 75,who attended to the dental clinic of this hospital from May 2019 to May 2021 were selected.All subjects were divided into experimental group A,B,C and the control group, with 40 cases in each group. The patients of control group was treated with chlorhexidine gargle. The patients of experimental group A was treated with tongue brush and scraping. The patients of experimental group B was treated with ultrasonic scaler. The patients of experimental group C was treated with tongue brush, scraping and ultrasonic scaler. The sensory method was used to detect oral rank (OR), and the volatile sulfur compounds (VSCs) detector was used to detect the VSCs value of the patient, while the tongue coating thickness (Tt) and tongue coating area (Ta) were analyzed before and after treatment. The periodontal pocket probing depth (PD) and plaque index (PLI) were detected to explore the relationship between periodontal disease, tongue coating and bad halitosis. Results After treatment, the values of OR and VSCs in the four groups decreased significantly (P<0.05). There were no significant differences in OR and VSCs between the experimental group A and the control group (P>0.05). The OR and VSCs values of experimental group B and C were significantly lower than those of the control group and the experimental group A (P<0.05). The OR and VSCs values of the experimental group C were significantly lower than those of the experimental group B (P<0.05). The values of Tt, Ta, PD and PLI in the control group had no significant change before and after treatment (P>0.05). The values of Tt and Ta in the experimental group A and the experimental group C reduced significantly than those before the treatment (P<0.05), but there was no significant difference between the two groups (P>0.05). The values of PD and PLI in the experimental group B and C reduced significantly. The values of PD and PLI in the experimental group C after treatment were significantly lower than those of the experimental group B (P<0.05). The results of correlation analysis showed that VSCs and OR had a significant positive correlation (r=0.852,P<0.05). VSCs, OR and Ta had a strong positive correlation (r=0.487,0.394,P<0.05), a weak correlation with Tt (r=0.288,0.265,P<0.05). OR and PLI had a strong positive correlation (r=0.678,0.524,P<0.05), and a weak correlation with PD (r=0.257,0.240,P<0.05). Conclusion The value of OR in the elderly has a positive correlation with the VSCs, Ta and PLI. Ultrasonic cleaner combined with tongue brush and scraping can significantly improve the halitosis of the elderly, reduce the level of VSCs, and improve the level of Tt, Ta, PD and PLI. [ABSTRACT FROM AUTHOR]