Compare the Efficacy and Safety of Dec-FB4 and FB4 as Conditioning Regimen for AML-MR

Inclusion Criteria: * Age 16-65 years and with an ECOG physical fitness score of 0-2 and an HCT-CI of less than 3; * Diagnosis: All enrolled cases were diagnosed with acute myeloid leukemia (AML-MR) after bone marrow cytomorphology, cytochemistry, immunophenotyping, chromosomal examination, and gene mutation, and achieved hematological remission (bone marrow smear primitive cells \<5%) and negative MRD before transplantation. * Have a medically qualified and suitable hematopoietic stem cell donor, including HLA-allogamous sibling donors, unrelated donors (HLA high-resolution 9-10/10 compatible) or related haploidentical donors; * No dysfunction of the heart, liver, lungs, kidneys, or other important organs, as defined as follows: ALT and AST ≤3 times the upper limit of normal; total bilirubin ≤2 times the upper limit of normal); BUN and Cr ≤1.25 times the upper limit of normal; electrocardiograms not suggestive of acute myocardial infarction or serious arrhythmias; cardiac echocardiography left ventricular ejection fraction ≥50%, no significant cardiac enlargement, valvular disease, or congenital heart disease; pulmonary function examination FEV1, FVC, DLCO ≥ 60% of the predicted value. * The patient and his/her legal representative have the desire and requirement to undergo hematopoietic stem cell transplantation and sign an informed consent, willingness and compliance with the treatment plan, follow-up schedule, laboratory tests, etc. Exclusion Criteria: * AML in unremitting stage; or BM in remission but with concurrent CNS leukemia or presence of extramedullary lesions; * Active hepatitis B (HBV-DNA ≥1×10\^3 copies/ml); * HIV-infected patients; * Active infections requiring intravenous antibiotic therapy; * There is severe impairment of vital organ function: respiratory failure, heart failure, decompensated hepatic insufficiency, renal insufficiency, etc; * Patients who use drugs or chronic alcohol abuse to the extent that it interferes with the evaluation of test results; * Mentally challenged/unable to obtain informed consent; * Those judged by the investigator to be unsuitable for participation in this trial.