• The written informed consent form shall be signed before proceeding with any study-related procedure.

• Participants shall be a female, aged 18 years or older.

• Histologically confirmed primary high-grade epithelial ovarian cancer, fallopian tube carcinoma or primary peritoneal carcinoma。

• FIGO staging is Stage III or IV.

• Patients who have undergone primary tumor reductive surgery or intermittent tumor reductive surgery (patients who have used neoadjuvant therapy), regardless of postoperative residual lesion status

• Participants must have received, prior to enrollment, a minimum of 2 cycles of bevacizumab in combination with platinum-based chemotherapy.

• Participants must have completed front-line, platinum-based chemotherapy with CR, PR, or NED assessed by RECIST v1.1.

• Participant must have either CA-125 in the normal range or CA-125 decrease by more than 90% during front-line therapy that is stable for at least 7 days (ie, no increase \> 15% from nadir).

• Participants must have first study treatment dose within 12 weeks of the first day of the last cycle of chemotherapy.

⁃ Genetic testing of tumor tissue indicates HRD positive or germline/somatic BRCA mutation prior to enrollment.

⁃ Participant must have an Eastern Cooperative Oncology Group (ECOG) score ≤2.

⁃ Organ function is in good condition, including: Hemoglobin ≥100 g/L; White blood cell count ≥3×10\^9/L; Neutrophil count ≥1.5×10\^9/L; Platelet count ≥100×10\^9/L; Total bilirubin is not more than 1.5 times the normal upper limit; ALK, AST and ALT are not more than 2.5 times their normal upper limit, and with existence of hepatic metastasis, these values must not be more than 5 times their normal upper limit; Serum creatinine is not more than 1.5 times the normal upper limit.