Objective To explore the effect of 5-aminolevulinic acid photodynamic therapy(ALA-PDT)combined with interferon suppository on clearance rate of human papilloma virus (HPV)and vaginal microenvironment in patients with persistent high-risk HPV infection.Methods A total of 80 patients with persistent high-risk HPV infection in Jingdezhen NO.1 People's Hospital were enrolled as the research objects from January 2020 to January 2023.According to random number table method,they were divided into control group and observation group,with 40 cases in each group.The control group was treated with interferon suppository,and the observation group was treated with interferon suppository combined with ALA-PDT.The changes in viral load,HPV clearance rate,density and diversity of floras,dominant bacteria,vaginal pH,Nugnet scores,and recurrence rate within 6 months in both groups were observed.Results After treatment,viral load in observation group was lower than that in control group,and HPV clearance rate was higher than that in control group,with statistically significant differences(P＜0.05).After treatment,the normal rate of flora density,the normal rate of flora diversity,and the health rate of dominant flora in the observation group were higher than those in the control group,and the differences were statistically significant (P＜0.05).After treatment,the vaginal pH and Nugnet score in observation group were lower than those in control group,with statistically significant differences (P＜0.05).The recurrence rate within 6 months in observation group was lower than that in control group,with a statistically significant difference (P ＜0.05).Conclusion ALA-PDT combined with interferon suppository can increase HPV clearance rate,improve vaginal microenvironment and reduce recurrence rate in patients with persistent high-risk HPV infection.