This study is a single-arm, open-label, exploratory clinical study, the main purpose is to evaluate the combination of envafolimab, lenvatinib VP-16 in the treatment of platinum-resistant recurrent epithelial ovarian cancer，primary fallopian tube cancer and primary peritoneal carcinoma.

Platinum-resistant patients who have received at least 1 line chemotherapy in the past and the recurrence time is less than 6 months will receive envafolimab combined with lenvatinib and VP-16 for 6 cycles, followed by single-agent envafolimab maintenance therapy until disease progression, intolerable toxicity, or withdrawal of informed consent

Inclusion Criteria:

• ≥18 years；
• ECOG 0-1
• Life expectancy of at least 3 months；
• Histologically or pathologically confirmed epithelial ovarian cancer (EOC), fallopian tube cancer, primary peritoneal cancer； Ovarian cancer patients with drug-resistant recurrence after platinum-based chemotherapy；
• At least one measurable objective tumor lesion by spiral CT examination, the maximum diameter ≥ 1cm（according to RECIST 1.1）；
• Satisfactory main organ function，laboratory test must meet the following criteria: hemoglobin (HGB) ≥90g/L, neutrophil count（ANC） ≥1.5×109/L, platelet count（PLT） ≥80×109/L, Serum creatinine（CR）≤1.5 upper normal limitation (UNL)，total bilirubin (TBil) ≤1.5 upper normal limitation (UNL), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤2.5 UNL (For patients with liver metastasis, the AST/ALT must be ≤5.0 UNL), Activated partial thromboplastin time (APTT), international normalized ratio (INR), prothrombin time (PT) ≤ 1.5×ULN; left ventricular ejection fraction (LVEF) ≥ 50%; thyroid stimulating hormone (TSH) within the normal range Within: if the baseline TSH exceeds the normal range, subjects with total T3 (or FT3) and FT4 within the normal range can also be enrolled;
• Subjects of childbearing potential must use an appropriate method of contraception during the study period and within 120 days after the end of the study, have a negative serum pregnancy test within 7 days prior to study enrollment, and must be non-lactating subjects；

Exclusion Criteria:

• Suffered from other malignant tumors within 5 years before the start of treatment in this study;
• Grade ≥1 unresolved toxicities (according to the most recent version of the National Cancer Institute [NCI] Common Terminology Criteria for Adverse Events [CTCAE]) due to any prior therapy, excluding alopecia and fatigue; neurotoxicity was Recovery to ≤ grade 1 or baseline before the group;
• Subjects with any severe and/or uncontrolled disease ；
• Poorly controlled diabetes (fasting blood glucose [FBG] > 10 mmol/L) ；
• Received major surgical treatment, incisional biopsy, or significant traumatic injury within 28 days prior to the start of study treatment; or had a long-term unhealed wound or fracture；
• Serious arterial/venous thrombotic event within 6 months prior to initiation of study treatment ；
• Previously received drug therapy against PD-1, PD-L1 and other related immune checkpoints ；
• Participating in or participating in other clinical investigators within 4 weeks prior to the start of the study ；
• Allergic to the active ingredients or excipients of the study drug ；
• Unsuitable for the study or other chemotherapy determined by investigator.