This study aimed to assess the efficacy and safety of 5-ALA-PDT for treating cervical LSIL and HR-HPV in women of childbearing age. A retrospective analysis was conducted on 237 patients (aged 20–40 years) who underwent 5-ALA-PDT at Minhang Hospital between 2022 and 2024. The treatment protocol involved topical application of 5-ALA, followed by 635-nm laser therapy at a power of 100 J/cm², administered over a duration of 30 min, and repeated in three sessions, with a spacing of one to two weeks between each session. Follow-up: 1 month (adverse reactions, cervical structure); 3–6/12 months (HR-HPV clearance, LSIL regression). The IBM SPSS 26.0 software was used for the analysis of the data, with a significance level of P < 0.05 being established as significant. The HR-HPV clearance study revealed that the success rate increased from 67.09% (3–6 months) to 88.19% (12 months), with a higher success rate observed in younger patients (P = 0.014/0.018). The following regressions were observed: LSIL regression of the cervical (98.82% to 99.44%), cervical canal (86.30% to 100%), and vaginal (82.25% to 96.77%) epithelium, with a 3–6-month cervical regression greater than that of other sites (P = 0.03). In this study, 65.82% of patients had no adverse reactions, with mild events (e.g., bleeding 22.78%, adhesions 14.34%) resolving within five days. The study concluded that 5-ALA-PDT is a safe and effective treatment for cervical LSIL combined with HR-HPV in women of childbearing age. This treatment promotes HR-HPV clearance and LSIL regression, preserves cervical structure, and accelerates HPV clearance in younger patients.