Horizontal semicircular canal benign paroxysmal positional vertigo(HSC-BPPV) is the second most common type of BPPV. It is difficult to diagnose and treat, which has a serious impact on the prognosis of patients. To study the clinical features of HSC-BPPV and the influencing factors of residual dizziness (RD). The clinical data of 358 patients with BPPV were retrospectively collected. The differences between HSC-BPPV and posterior semicircular canal benign paroxysmal positional vertigo (PSC-BPPV) were compared, and the influencing factors of RD after HSC-BPPV repositioning were analyzed. ① Compared with PSC-BPPV, HSC-BPPV had a lower success rate of first repositioning (64.7 vs. 75.0%), a higher incidence of RD (57.3 vs. 43.8%), and a higher DHI score (40.0 vs. 34.0), and the differences were statistically significant (p<.05). ② Logistic regression analysis showed that age ≥60 years, secondary, DHI score, successful first repositioning were the influencing factors for the development of RD after HSC-BPPV repositioning (p<.05). The diagnosis and treatment of HSC-BPPV is difficult, and RD is prone to occur. Clinicians need to strengthen the training of HSC-BPPV diagnosis and treatment to reduce the occurrence and progression of RD.