• Voluntary signed informed consent (ICF) and follow protocol requirements

• Age is 18\

‣ 75 years old (including the boundary value), gender is not limited

• Patients with advanced solid tumors who have histologically or cytologically confirmed standard therapy failure (progressive treatment or intolerance), or no standard therapy regimen, or who are not suitable for standard therapy at this stage

• Dose escalation study (Phase Ia): Participants agreed to provide fresh or archived tumor tissue samples for assessment of CLDN18.2 expression levels before the first dose (central laboratory), and subjects enrolled in Phase Ia did not require positive CLDN18.2 expression. If the subject cannot provide samples or a sufficient number of slices, he may be evaluated by the investigator if other entry criteria are met

• Dose extension study (Phase Ib): The subject agreed to provide fresh or archived tumor tissue samples for the assessment of CLDN18.2 expression levels (before the central laboratory) and tested positive for CLDN18.2 by the central laboratory

• According to RECIST v1.1 standard, dose escalation studies (Phase Ia) have at least evaluable lesions; Dose extension study (Phase Ib) with at least one measurable lesion;

• The ECOG physical strength score is 0-1 point

• The estimated survival time is not less than 3 months

• The toxicity of previous anti-tumor therapy has recovered to grade 1 as defined by CTCAE v5.0 (except for asymptomatic laboratory abnormalities, such as elevated ALP test, hyperuricemia, elevated blood glucose, etc.

• except for toxicity without safety risk judged by the investigator, such as hair loss, pigmentation, grade 2 peripheral neurotoxicity, thyrotoxicity after immune checkpoint inhibitor treatment, except for those who have been controlled after hormone replacement therapy)

⁃ Within 7 days before the first dose, the functional levels of the bone marrow reserve and organs must meet the following requirements: Bone marrow reserve: Absolute neutrophil count (ANC) 1.5 109 / L, platelet count (PLT) 90109 / L, hemoglobin (HGB)\> 90 g / L (no blood transfusion or hematopoietic stimulating factor therapy within 14 days) Coagulation function: activated partial prothrombin time (APTT) extended 1.5 upper limit of normal (ULN), international standardized ratio (INR) 1.5 Liver function: total bilirubin 1.5 ULN (direct bilirubin normal Gilbert syndrome can be enrolled), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) 2.5 ULN (if liver metastases, ALT and AST 5 ULN) Renal function: creatinine clearance of 60 mL/min (using the Cockcroft-Gault formula, see Appendix 1) or serum creatinine of 1.5 ULN Qualified fertile patients (men and women) must agree to use reliable contraceptive methods (hormone or barrier method or abstinence, etc.) with their partner during the trial and at least 6 months after the last dose

⁃ Qualified patients (male and female) with fertility must agree to use reliable contraceptive methods (such as hormone or barrier methods or abstinence) with their partners during the trial period and at least 6 months after the last medication; Female patients of childbearing age must have a negative serum pregnancy test within 7 days before the first use of the investigational drug.