This study is a single center, single arm, open study design. The main purpose of this study is to evaluate the tolerance and efficacy of SHR1701 with synchronous radiotherapy in patients with metastatic non-small cell lung cancer who have failed after systematic treatment. Large fraction radiotherapy is given to all lesions as much as possible, and low-dose radiotherapy is given to the lesions that cannot be tolerated or have no obvious benefit.

Inclusion Criteria:

• Subjects voluntarily participate in this study and sign informed consent.
• NSCLC in stage IV.
• No clear driven genes (including but not limited to EGFR、ALK、ROS1、cMET).
• Previously received more than 1 chemotherapy regimen and progressed/ recurred.
• At least one lesion is suitable for hypofraction radiotherapy.
• There is at least one measurable lesion.
• 18 to 75 years old
• ECOG 0-1
• The function of vital organs meets the following requirements. ANC ≥ 1.5×10^9/L, PLT≥100×10^9/L, Hb≥9g/dL, ALB≥3g/dL, TSH ≤ULN, Bilirubin ≤ 1 times ULN; ALT and AST ≤1.5 times ULN. AKP ≤ 2.5 times ULN. CREA ≤1.5 times ULN or CCr≥60mL/min#
• The estimated survival period is more than 3 months.
• Female Subjects of childbearing potential must have a negative serum pregnancy test within 72 hours before the first dose and must be willing to use very efficient barrier methods of contraception for the course of the study through 3 months after the last dose of study treatment

Exclusion Criteria:

The subjects had any history of autoimmune disease or active autoimmune disease.

• Subjects are using immunosuppressive agents, or systemic, or absorptive, local hormone therapy to achieve immunosuppression.It is still in use within 2 weeks of the entry.
• Subjects with severe allergic reactions to other monoclonal antibodies.
• The subjects had a central nervous system metastases of clinical symptoms.
• Central squamous cell lung carcinoma.
• Imaging (CT or MRI) shows that tumors invade large blood vessels or are indistinct with blood vessels.
• Imaging (CT or MRI) showed significant pulmonary vacuity or necrotic tumors,Borderline adenocarcinoma accompanied by a cavity can be considered after discussion with investigator.
• Failing to properly control the clinical symptoms or disease of the heart.
• Subjects had active infections.
• Subjects may receive other systemic antitumor therapy during the study period.
• Other clinical trials of drugs were used in the first four weeks of the first medication.