Inclusion Criteria:
* Voluntary agreement to provide written informed consent.
* female, Age 18 -75 years.
* Predicted survival ≥ 3 month.
* Histologically and/or cytologically confirmed Squamous cell carcinoma, adenocarcinoma, adenosquamous cell carcinoma, FIGO 2018 stage III-IVA.
* Unable to undergo curative surgery，Pior not received systemic therapy before CCRT, Including but not limited to radiotherapy, chemotherapy, immunotherapy, and biological therapy,etc.
* Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
* Have at least one evaluable lesion (RECIST 1.1 criteria)
* Adequate organ function, evidenced by the following laboratory results within 7 days prior to the study treatment.
* participants are eligible to participate if they agree to the contraception use as per study protocol.
* Willing to adhere to the study visit schedule and the prohibitions and restrictions specified in this protocol.
Exclusion Criteria:
* Has received other antitumor therapy before CCRT.
* Therapeutic evaluation of CCRT was disease progression.
* Previously received immune checkpoint inhibitors (such as anti-PD-1 antibodies, anti-PD-L1 antibodies, anti-CTLA-4 antibodies, etc.), immune checkpoint agonists (such as ICOS, CD40, CD137, GITR, and Ox40 . etc.), immune cell therapy. etc. Any tumor immune mechanisms treatment .
* With brain metastases.
* Previously received allogeneic stem cell or parenchymal organ transplantation.
* Previously or currently suffering from congenital or acquired immunodeficiency diseases.
* known or suspected to have a history of allergies to similar drugs, or has a history of hypersensitivity to chimeric or humanized antibodies or fusion proteins, or is allergic to excipients of the study drug.
* Diagnosed with HBsAg, HBcAb positive and HBV DNA copy positive, or HCVAb positive, or HIVAb positive.
* Has received a live virus vaccine within 4 weeks of planned start of trial treatment.
* Within the 6 months prior to enrollment, has serious cardiovascular events such as pulmonary embolism, acute myocardial infarction, congestive heart failure (New York Heart Association grade III or IV), and ≥ 2 grade ventricular arrhythmias.
* Cerebrovascular accident within 6 months prior to enrollment.
* Active infection requiring systemic treatment.
* Uncontrolled hypertension, diabetes, Interstitial lung Disease, non infectious pneumonia , pulmonary fibrosis, acute lung disease, etc.
* Required systemic treatment with glucocorticoid (\>10 mg/day of prednisone or equivalent glucocorticoid) or other immunosuppressive agents within 14 days prior to enter the trial.
* History of other malignancy within the previous 5 years, except for appropriately treated carcinoma in situ of the cervix, non-melanoma skin carcinoma, or cancers with a similar curative outcome as those mentioned above.
* Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.
* Pregnancy or lactation.
* Assessed by the investigator to be unable or unwilling to comply with the requirements of the protocol.
