Study of Thiotepa Combination With Melphalan (TM Protocol) Conditioning for Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma：A Prospective Randomized Controlled Clinical Trial

Inclusion Criteria: * 1\) Age 18-70 years old, gender is not limited; 2) Patients with confirmed multiple myeloma; 3) CR is not achieved before transplantation after treatment with or without extramedullary lesion invasion; 4) plan to undergo autologous hematopoietic stem cell transplantation; 5) recieve autologous hematopoietic stem cell transplantation within 12 months; 6) CD34 positive cell counts ≥2×106/kg; 7) The function of major organs is normal, and the laboratory test results meet the following criteria: a. Alanine aminotransferase (ALT) ≤3.0× upper limit of normal (ULN) aspartate aminotransferase (AST) ≤3.0×ULN; b. Serum total bilirubin ≤ 1.5×ULN; 8) Voluntarily participate in this clinical trial, understand the research procedures and be able to sign the informed consent forms Exclusion Criteria: * 1\) Do not have indications for autologous hematopoietic stem cell transplantation; 2) presence of uncontrolled active infection (HIV-positive, positive for HBV-DNA and HCV-RNA quantitative tests); 3) severe respiratory diseases; 4) Severe abnormal liver function; 5) a second transplant is required; 6) Clinically significant or uncontrolled heart disease (grade III or IV congestive heart failure, EF\<45%, BNP\>5000ng/ml, TnT\>0.06ug/L, oxygen saturation \<95%, any of which) 7) Patients with other solid tumors; 8) Those who are allergic to setepa and the drug involved in the study or have a more serious allergic constitution; 9) Those who participate in other clinical research at the same time; 10) Other conditions judged by the investigator to be unsuitable for inclusion in this study.