Inclusion Criteria: 1. The legal guardian of the subject fully understands the purpose, nature, methods, and possible risks of the study, and signs a written informed consent form; 2. The study includes ambulatory male subjects who are at least 4 years old and less than 8 years old (4 years old ≤ age \< 8 years old) ; 3. Genetically confirmed diagnosis of DMD; 4. Have at least 1 of the following typical clinical signs or laboratory abnormalities of DMD: proximal muscle weakness, waddling gait, pseudo gastrocnemius hypertrophy, Gower\'s sign, pterygoid scapula; 5. Ability to cooperate with motor assessment testing, magnetic resonance imaging (MRI) and muscle biopsy according to the requirements of the study. Exclusion Criteria: 1. Hepatitis B surface antigen (HBsAg) positive, hepatitis B virus deoxyribonucleic acid (HBV-DNA) ≥1000U/mL, hepatitis C virus ribonucleic acid (HCV-RNA) positive or human immunodeficiency virus (HIV) positive; 2. Receiving antiviral therapy for hepatitis B, hepatitis C, HIV, etc.; 3. Left ventricular ejection fraction (LVEF) \<50% or ≥ class III cardiac function defined by New York Heart Association (NYHA); 4. With severe or persistent arrhythmias and congenital heart disease. 5. The subject\'s preventive treatment/cardiomyopathy treatment changes within 1 month before the start of the study treatment; 6. With underlying liver disease, such as previous diagnosis of portal hypertension, splenomegaly, hepatic encephalopathy, or hepatic fibrosis ≥ stage 3; or nodules, cysts found by B-ultrasound in the past, or elevated alpha-fetoprotein in laboratory tests during the screening period, etc., and these abnormalities are judged by the investigator to be clinically significant;