Abstract: Objective: To analyze the correlation of vaginal microecology,high-risk human papillomavirus (HR-HPV) infection,and cervical squamous intraepithelial lesions (SIL). Methods: A total of 83 women with SIL were collected and divided into high-grade SIL (HSIL) group (n=40) and low-grade SIL (LSIL) group (n=43) according to the pathological examination results,and 45 healthy women undergoing physical examinations during the same period were included as the control group.The HPV infection,vaginal discharge leukocyte esterase (LE),sialidase (SNA),N-acetyl-β-D-galactosaminidase (NAG),hydrogen peroxide (H₂O₂) positive rate,pH value,and cleanliness of subjects in the three groups were compared.The correlation between SIL and HR-HPV infection,vaginal microecology was analyzed. Results: The positive rates of SNA,LE,NAG,H₂O₂,and pH value in the LSIL group and HSIL group were higher than those in the control group (P<0.05),and the infection rate of vaginal trichomonas and the positive rates of aerobic vaginitis (AV) and bacterial vaginosis (BV) were also higher than those in the control group (P<0.05).The proportion of vaginal cleanliness grade Ⅰ°-Ⅱ° in the LSIL group and HSIL group was lower than that in the control group,while the proportion of vaginal cleanliness grade Ⅲ°-Ⅳ° was higher than that in the control group (P<0.05).The HR-HPV infection rate and total incidence of HPV infection in the LSIL group and HSIL group were higher than those in the control group (P<0.05).Spearman analysis showed that SIL was significantly positively correlated with vaginal pH value,HR-HPV infection,vaginal cleanliness,LE,NAG,SNA,H₂O₂ positive rate,trichomonas infection rate,AV,and BV (P<0.01). Conclusions: SIL patients exhibit an imbalanced vaginal microecology.Cervical lesions are associated with HPV infection type,AV,BV,LE,NAG,SNA,H₂O₂ positive rates,pH value,and vaginal cleanliness.