This study is a prospective, multicenter, randomized controlled clinical trial planned to enroll 64 female patients with malignant hematologic diseases aged 14-50 years who are scheduled to undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT). Patients will be divided into two groups based on the use of myeloablative conditioning: the myeloablative conditioning (MAC) group and the non-MAC conditioning group. The non-MAC group refers to a primary conditioning regimen where the main conditioning agents-busulfan (Bu) ≤ 6.4 mg/kg, melphalan (Mel) ≤ 140 mg/m², and thiotepa ≤ 10 mg/kg-are combined. Patients receiving this primary chemotherapy regimen will be assigned to the MAC group. Within each group (MAC or non-MAC), patients were randomly assigned 1:1 to either the experimental group (goserelin prophylaxis) or the control group using a random number table. The experimental group received a single 3.6 mg subcutaneous injection of goserelin 1-3 days prior to conditioning, in addition to the standard transplantation regimen. The control group did not receive goserelin prophylaxis. The primary endpoint was menstrual recovery rate at 6 months post-transplantation. Secondary endpoints included: incidence of premature ovarian insufficiency (POI); ovarian reserve function markers: anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) levels; other reproductive indicators: ovarian volume, endometrial thickness; Neutrophil/platelet engraftment time; Complications: incidence of acute/chronic graft-versus-host disease (aGVHD/cGVHD), EBV/CMV infection rates; Disease recurrence rate; Transplant-related mortality; Adverse event (AE) occurrence. This study aims to evaluate the efficacy and safety of goserelin in improving ovarian function following hematopoietic stem cell transplantation in patients with malignant hematologic diseases.