To Evaluate Recombinant Human Follicle Stimulating Hormone-CTP Fusion Protein Injection or Placebo Combined With Chorionic Gonadotropin for Injection

Inclusion Criteria: * The guardian and subject are aware of the study procedures, available alternative treatments, and the risks of participating in the study, and voluntarily sign a written ICF to voluntarily participate in the study. * Age 14-18 years old (excluding 18 years old) at the time of signing the ICF, with bone age greater than 12 years old. * Height ≥145cm and body mass index (BMI) \< 30kg/m2 when signing ICF. * Diagnosis of idiopathic or congenital hypogonadotropic hypogonadism. * The presence of bilateral pre-gonadal onset testis during the screening period: testicular volume \<4 mL on each side (determined by ultrasound and evaluated by 2 qualified ultrasound specialists authorized by the researchers of the research center). * The circulating gonadotropin (Gn) level was low (FSH≤1 IU/L and LH≤1 IU/L) during the screening period, and the peak LH value of GnRH excitation test was ≤4 IU/L. * Serum testosterone T ≤ 1 ng/mL during the screening period. * The normal range of other pituitary hormones during the screening period (judged by the researcher). * Lesions detected by MRI on the head within 3 months before or during screening were normal or determined by the investigator to have no impact on the study. * Consent to the use of reliable contraception (e.g. abstinence, condoms, etc.) by yourself and your sexual partner during the study period and for 3 months after the study drug treatment. Exclusion Criteria: There is primary hypogonadism (e.g., Klinefelte…