A Comparative Study to Valuating the Efficacy and Safety of QL1206 and Prolia®

Inclusion Criteria: * Subjects who agree to participate in the study and sign the informed consent form. * Postmenopausal women who can walk freely, aged 50-85 years (including 50 and 85 years old). * Subjects whose absolute value of bone mineral density (BMD) in the lumbar or total hip area meets T values ≤ -2.5 and \> -4.0. * Subjects who must have at least one of the following risk factors: History of previous fragility fractures (occurring after the age of 40); history of hip fractures in fathers or mothers; increased bone turnover rate during screening; low body weight (BMI ≤ 19 kg/m2); advanced age (aged ≥ 65 years); current smoke. * The duration of spontaneous amenorrhea was \>2 years or \>2 years after bilateral oophorectomy. If the status of bilateral oophorectomy is unknown or if the ovaries are preserved after hysterectomy, follicle stimulating hormone (FSH) levels \>40mIU/mL may be used to confirm the status of postoperative menopause. Exclusion Criteria: * Bone/metabolic disease. * Hyperparathyroidism or hypoparathyroidism. * Thyroid condition: Hyperthyroidism or hypothyroidism. * Rheumatoid arthritis. * Malabsorption syndrome. * Renal disease - severe impairment of kidney function. * Vitamin D defViciency (25-hydroxyvitamin D, 25OHD \<20 ng/mL). * Oral or dental diseases: previous or current evidence of mandibular osteomyelitis or osteonecrosis; Acute dental or mandibular disease requiring oral surgery; Planning invasive dental surgery; Failure to recover from dental or oral surgery. * Previously used denosumab drugs. * Use of intravenous bisphosphonates, fluoride, or strontium to treat osteoporosis within the last 5 years. * OOral bisphosphonates (used for at least 3 years, or used for less than 3 years but more than 3 months, with the last use occurring \<1 year before the ICF). * Use of any of the following drugs within 6 weeks prior to screening that may affect bone metabolism. * History of more than two vertebral fractures. * Malignant tumors.