Human Umbilical Cord-derived Mesenchymal Stem Cells for Decompensated Cirrhosis (MSC-DLC-2)

Inclusion Criteria: 1. Willing to provide written informed consent; 2. Aged 18 to 75 years (including 18 and 75 years), male or female; 3. Patients diagnosed with decompensated liver cirrhosis based on clinical findings, laboratory tests, imaging findings and/or representative pathological findings (decompensated liver cirrhosis is defined as the occurrence of at least one serious complication, including esophageal and gastric varices bleeding, hepatic encephalopathy, ascites, spontaneous bacterial peritonitis and other serious complications); 4. The Model for End-stage Liver Disease (MELD) score 15 to 30 points. Exclusion Criteria: 1. Appearance of active variceal bleeding, overt hepatic encephalopathy (HE), refractory ascites or hepatorenal syndrome within 1 month prior to screening visit. 2. Uncontrolled severe infection within 2 weeks of screening. 3. Patients with hepatitis B virus-related decompensated liver cirrhosis may discontinue antiviral therapy during the study, or those who with antiviral therapy for HBV for less than 12 months, or hepatitis B virus (HBV) DNA ≥ detection limit at the time of screening. 4. Patients with hepatitis C virus-related decompensated liver cirrhosis may discontinue antiviral therapy during the study, or those who with antiviral therapy for HCV for less than 12 months, or hepatitis C virus (HCV) RNA ≥ detection limit at the time of screening (except HCV RNA\< detection limit without any antiviral treatment). 5. Patients under treatment with corticosteroids for autoimmune hepatitis for less than 6 months. 6. Trans-jugular intrahepatic portosystemic shunts (TIPS) insertion within 6 months prior to study inclusion. 7. Active drinkers with alcohol-related decompensated cirrhosis are unwilling to stop alcohol abuse after inclusion. 8. Significant renal insufficiency (serum creatinine ≥ 1.2 times upper normal limit); Severe electrolyte abnormality (serum sodium level \< 125 mmol/L); Severe leukopenia (white blood cell count \< 1 × 10E9/L). 9. Patients with biliary obstruction, or portal vein spongiosis. 10. Patients with surgical history such as splenic cut-off flow. 11. Patients with malignant tumors within 5 years, except those with basal cell carcinoma, squamous cell carcinoma and/or carcinoma in situ who had received curative treatment and curative resection. 12. Patients with a prior history of major organ transplantation or complicated with significant disease of heart, lung, kidney, blood, endocrine and other systems. 13. Drug abuse, drug dependence and patients who receive methadone treatment or with psychosis. 14. Against the human immunodeficiency virus antibody (Anti - HIV) or syphilis antibody test results were positive. 15. Pregnancy, lactation or with recent fertility plan during the test and 6 months after the test. 16. Highly allergic, or have a history of severe allergies, known severe allergies to the investigational drug or any of the excipients. 17. History of pulmonary embolism. 18. Patients who had previously received stem cell therapy or were intolerant to cell therapy. 19. The proposed line of liver transplants within three months. 20. Participants in other clinical trials within the last 3 months. 21. Any other clinical condition which the investigator considers would make the patient unsuitable for the trial.