Inclusion Criteria:  Patients must be between 18 and 70 years old (including 18 and 70 years old), male or female; Patients with advanced solid tumors (stage IV): non-small cell lung cancer (NSCLC); Gastric adenocarcinoma; Colorectal adenocarcinoma, etc ; Patients must have an ECOG performance status of 0-1; Patients must have a life expectancy ≥ 12 weeks;  Patients must have adequate organ function:  White blood cell (WBC) count≥4.0x10^9/L or absolute neutrophil count (ANC) ≥1.5 x 10^9/L, Platelets ≥100 x 10^9/L, Hemoglobin≥ 90g/L ; thrombin time or Activated partial thromboplastin time≤1.5ULN; liver and renal function: Total bilirubin≤1.5ULN (upper limit of normal), Alanine aminotransferase (ALT) or aspartate aminotransferase (AST)≤2.5ULN or ≤5ULN (subjects with liver metastasis), alkaline phosphatase (ALP)≤ 2.5ULN (if there is bone metastasis or liver metastasis ALP≤4.5ULN). Urea (BUN)≤1.5ULN, creatinine≤1.5ULN;  Patients must have ≥1 measurable lesion according to RECIST1.1 criteria; For patients who have partners of childbearing potential: Partner and/or patient must use a method of birth control with adequate barrier protection, deemed acceptable by the principle investigator during the study and for 6 months after last study drug administration.; Patients must have the ability to understand and sign an approved ICF.  Exclusion Criteria:  There are any of the following conditions, such as brain metastasis (except for asymptomatic primary or metastatic brain tumors that do not need treatment), carcinomatous meningitis, myocardial infarction (within 6 months before enrollment), unstable angina pectoris, or high risk of uncontrollable arrhythmia, coronary artery bypass grafting, cerebrovascular accident (within 6 months before enrollment), congestive heart failure (cardiac function grade III-IV), pulmonary embolism, deep venous thrombosis, Infections that need to be treated with intravenous antibiotics within 2 weeks, and immunosuppressant therapy after organ transplantation; Primary central nervous system tumor; HBV DNA≥1000 copies/ml; HCV-RNA≥1000 copies/ml; People with positive antibodies to HIV or syphilis; Patients with acute or subacute intestinal obstruction, or a history of inflammatory bowel disease; Women who are pregnant, breastfeeding or planning pregnancy; People who are known to be allergic to the study preparation or its auxiliary materials; People with a history of psychotropic substance abuse and inability to get rid of it or mental disorders; Patients who cannot lie for half an hour; Patients who are allergic to any component of the imaging agent or antibody; Patients who cannot accept PET/CT imaging; Situations that other researchers consider unsuitable to participate in the trial.