To compare the efficacy of two different dosage regimens of intravenous immune globulin (IVIG) in the treatment of children with newly diagnosed immune thrombocytopenia, and to reduce related adverse reactions and economic burdens on the premise of ensuring the remission rate

Inclusion Criteria:Subjects enrolled in this study must meet all of the following criteria:

1. Meet the diagnostic criteria of ITP and be diagnosed for the first time without treatment
2. Age > 28 days and ≤ 14 years old
3. PLT<20×109/L
4. Have signed the informed consent

Exclusion Criteria:Anyone who has any of the following conditions will not enter the clinical study:

1. Intracranial hemorrhage or severe gastrointestinal or urinary tract hemorrhage requiring emergency treatment, such as simultaneous use of platelet transfusion and glucocorticoid therapy
2. Received glucocorticoid or IVIG therapy within 6 months
3. Weight > 40kg
4. Menstrual female patients
5. Patients with underlying diseases such as tumor diseases, autoimmune diseases or genetic diseases
6. Patients who have received radiotherapy and chemotherapy
7. There are any significant abnormal coexisting diseases or mental illnesses that affect the patient's life safety and compliance, and affect informed consent, research participation, follow-up or interpretation of results -