Inclusion Criteria:  At least 3 ~ 17 years old (both included); The subject voluntarily agrees to participate in the study, and / or the guardian of the subject voluntarily agrees to the child to participate in the study. The subject himself (8-17 years old) and the guardian sign the informed consent form, and can provide valid identity certificates to understand and comply with the requirements of the test protocol; The subject and / or the guardian of the subject have the ability to understand (non illiterate) the research procedures and promise to participate in regular follow-up according to the research requirements; There is no high or medium risk area, overseas travel history or residence history in the past 14 days; In the past 14 days, no confirmed case of New Coronavirus infection, asymptomatic infection or suspected cases had been found. And there was no contact history of patients with fever or respiratory symptoms from high and medium risk areas in the past 14 days; Personnel in non isolation period; Male and female subjects with fertility agreed to take effective contraceptive measures from the beginning of the study to 2 months after the whole vaccination.  Exclusion Criteria:  The results of physical examination during screening period are abnormal and clinically significant (not suitable for vaccination) as determined by clinicians; Suspected or confirmed fever within 72 hours before enrollment (including the day of enrollment) (> 14 years old, axillary temperature ≥ 37.3 ℃; ≤ 14 years old, axillary temperature ≥ 37.5 ℃); Have a history of severe allergy to any component of the test vaccine, including aluminum preparation, such as anaphylactic shock, allergic laryngeal edema, allergic purpura, thrombocytopenic purpura, dyspnea, angioneurotic edema, etc; Or have a history of the above serious side effects after the use of any vaccine or drug in the past; had previous history of SARS and SARS-CoV-2. Taking antipyretics or painkillers within 24 hours before the first dose of vaccine; persons who have been vaccinated with New Coronavirus or inoculated with live attenuated vaccine within 7 days or within 7 days before the first dose of vaccine are inoculated with inward subunit vaccine and / or inactivated vaccine. Have received blood or blood related products, including immunoglobulin, within 3 months before the vaccination of the test vaccine; Or planned use during the study;  Persons suffering from the following diseases:  ① Digestive system diseases (such as diarrhea, abdominal pain, vomiting, etc.) in the past 7 days;  ② Suffering from congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc;  ③ History of congenital or acquired immune deficiency or autoimmune diseases or receiving immunomodulator treatment within 6 months, such as immunosuppressive dose of Glucocorticoid (dose reference: equivalent to prednisone 20mg / day, more than one week); Or monoclonal antibody; Or thymosin; Or interferon, etc; However, topical medication (such as ointment, eye drops, inhalants or nasal sprays) is allowed;  ④ It is known that it is diagnosed with infectious diseases, such as active tuberculosis, viral hepatitis present, human immunodeficiency virus infection or Treponema pallidum infection.  ⑤ Neurological diseases or neurodysplasia (e.g., convulsions, migraines, epilepsy, stroke, seizures in the last three years, encephalopathy, focal neurological deficit, Guillain Barre syndrome, encephalomyelitis or transverse myelitis); History of psychosis or family history;  ⑥ Functional absence of spleen, and absence of spleen or splenectomy for any reason;  ⑦ There are serious chronic diseases or disease in progress can not be controlled smoothly, such as diabetes, drugs can not control hypertension.  ⑧ Severe liver and kidney diseases; Respiratory diseases that currently require daily drug treatment (e.g., chronic obstructive pulmonary disease [COPD], asthma) or any treatment for aggravation of respiratory diseases (e.g., aggravation of asthma) in the last 5 years; A history of serious cardiovascular disease (such as congestive heart failure, cardiomyopathy, ischemic heart disease, arrhythmia, conduction block, myocardial infarction, cor pulmonale) or myocarditis or pericarditis;  ⑨ Thrombocytopenia, any coagulation dysfunction or anticoagulant treatment;  ⑩ Cancer patients (except basal cell carcinoma);  Lactating women or pregnant women (including women of childbearing age with positive urine pregnancy test), or women or their partners who have pregnancy plans within 2 months after the whole vaccination of the test vaccine; Those who have participated or are participating in other clinical trials, and the relevant visits have not been completed, or are clearly vaccinated after the completion of the new crown vaccine; The researcher believes that the subject has any disease or condition that may put the subject at unacceptable risk; The subjects were unable to meet the protocol requirements; Interference with the evaluation of vaccine response.