( 1) At the time of signing the informed consent form, be at least 18 years of age, both male and female.

(2) Bone marrow hematopoietic function satisfies: white blood cell count≥3×10^9/L; Centrocyte count ≥1×10^9/L (no colony-stimulating factor received within 2 weeks prior to screening); Hemoglobin ≥ 60g/L.

(3)ALT≤3×ULN; AST≤3×ULN； TBIL≤3×ULN。 (4) Renal function satisfaction: creatinine clearance CrCl≥30mL/min. (5) INR≤1.5×ULN , PT≤1.5×ULN. (6)RA:Documented diagnosis of RA which fulfills the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Classification Criteria ; 3 months after use of 1 or more csDMARDs and 1 or more bDMARDs prior to screening: 1) DAS28-ESR>3.2 or CDAI>10; or 2) the dose of the hormone (prednisone or equivalent) cannot be reduced to less than 7.5 mg/day; or 3) the number of swollen and/or tender joints ≥3; Treatment with stable 1 or more cs DMARD(s) and/or bDMARDs prior to enrollment as follows: methotrexate for at least 12 weeks and at a dose of 7.5-25mg/week for at least 4 weeks; Stable use of hydroxychloroquine dose ≤ 400 mg/day for at least 4 weeks; Stable oral sulfasalazine for at least 4 weeks 1~3 g/d; Stable oral leflunomide 10-20 mg/day for at least 4 weeks.

(7)systemic lupus erythematosus : Diagnosis of systemic lupus erythematosus according to the SLE classification criteria of the 2019 EULAR/ACR; History of systemic lupus erythematosus for at least 6 months prior to screening and active disease for 2 months after use of standard treatment regimens prior to screening; BILAG-2004 assesses the presence of at least 1 Grade A or 2 Grade B organ scores; Positive antinuclear antibody, or positive anti-ds-DNA antibody, or positive anti-Sm antibody; SLEDAI-2000 score ≥8 during the screening period.

(8)Sjögren's syndrome : Diagnosis of Sjögren's syndrome according to the 2002 International Classification of Primary Sjögren's Syndrome or the 2016 ACR/EULAR classification criteria; Diagnosed with pSS-TP and platelet count < 30×10^9/L; Sjögren's syndrome Disease Activity Index (ESSDAI) score ≥5 during the screening period; Sjögren's syndrome for at least 6 months prior to screening and active disease 2 months after use of conventional treatment regimens prior to screening. Use of immunomodulatory drugs for more than 6 months.

(9)systemic sclerosis : Diagnosis of systemic sclerosis according to the 2013 ACR classification criteria for systemic sclerosis. Positive antinuclear antibody at screening. Presence of clear evidence of HRCT progression. History of systemic sclerosis prior to screening for at least 6 months and active disease for 2 months after use of conventional treatment regimens prior to screening.