Objective: To analyze the risk factors of postoperative infection after high intensity focused ultrasound (HIFU) in gynecology department, and to evaluate the effect of pelvic inflammatory disease treatment on postoperative infection after HIFU. Methods: A total of 100 female patients who underwent HIFU ablation in Jiangmen Xinhui District Maternal and Child Health Care Hospital from April 1, 2024 to January 31, 2025 were selected. Univariate analysis and Logistic regression analysis were used to identify the influencing factors of postoperative infection. Patients with postoperative infection after HIFU were divided into the observation group and the control group by random number table method. The observation group was treated with pelvic inflammatory disease treatment, and the control group was treated with prophylactic antibiotics. The clinical efficacy, laboratory indexes and disappearance time of clinical symptoms were compared between the two groups. Results: Postoperative infection occurred in 42 patients (42.00%) after HIFU. Univariate analysis showed that treatment time (＞60 min), energy input (＞200 kJ), and preoperative uterine cavity operations (electroresection, curettage) significantly affected the occurrence of postoperative infection after HIFU (P＜0.05), while age and disease type had no significant effect (P＞0.05). Logistic regression analysis indicated that treatment time, energy input, and preoperative uterine cavity operations (electroresection, curettage) were independent risk factors for postoperative infection after HIFU (P ＜ 0.05). The total effective rate of clinical efficacy in the observation group was 95.24%, which was significantly higher than 71.43% in the control group (P＜0.05). There was no significant difference in white blood cell (WBC), C-reactive protein (CRP), and procalcitonin (PCT) levels between the two groups before treatment (P＞0.05). After 14 days of treatment, the levels of WBC, CRP, and PCT in the observation group were lower than those in the control group (P＜0.05). The disappearance time of abdominal pain and the time for body temperature to return to normal in the observation group were shorter than those in the control group (P＜0.05). Conclusion: Postoperative infection after HIFU is a major factor affecting the recovery of gynecological patients. Its occurrence is mainly related to treatment time ＞60 min, energy input ＞200 kJ, and preoperative uterine cavity operations (such as electroresection and curettage), while age and disease type have a relatively small impact. The pelvic inflammatory disease treatment regimen for postoperative infection after HIFU can significantly improve clinical efficacy, improve inflammatory indicators, and shorten the time for abdominal pain and body temperature to return to normal, providing new ideas for the prevention and treatment of postoperative infection after HIFU.