Evaluate the Safety and Efficacy of Xiyanping in Pediatric Participants With Severe Influenza-Like Symptoms

Inclusion Criteria: * Age between 3 and 6 years old; * Clinical diagnosis of Severe Influenza with hospital treatment needed; * Patients did not accept oseltamivir phosphate treatment or symptoms persisted for more than 3 days treatment; （1)Fever ≥ 39°C (tympanic temperature) for at least 3 days with Severe cough,sputum, blood stasis, or chest pain; （2）Combined pneumonia; * The rapid viral antigen test of throat swab and nose swab results were positive; * Guardians understood and assigned the informed consent; Exclusion Criteria: * Participants allergenic to XiYanPing injection, Andrographolide or Oseltamivir Phosphate; * Creatinine clearance \<80ml/min or received continuous renal replacement therapy (CRRT) test; * Need extracorporeal membrane oxygenation (ECMO) at baseline; * Glasgow Coma Rating Scale (GCS) score ≤ 9 points when dyspnea, altered consciousness, severe vomiting, or coma appeared at baseline; * Crisis influenza Symptoms, such as respiratory failure, acute necrotizing encephalopathy, septic shock, multiple organ dysfunction and other serious clinical conditions requiring monitoring; * Use of systemic steroids or other immunosuppressants; * Participants with the following underlying diseases, including: heart disease (such as New York Heart Function Classification II-IV) or clinically significant arrhythmia (such as QTc ≥ 480ms), malignant tumor or other malignant diseases, autoimmune diseases; liver and kidney diseases ( ALT and AST ≥ 1.5 × ULN; Cr and BUN \> 1.2 × ULN), blood diseases, nervous system diseases, immune system diseases and endocrine diseases, consciousness, speech, behavioral abnormalities caused by encephalitis / encephalopathy or limb paralysis, severe malnutrition, etc. * Participants used Influenza virus vaccine within 3 months; * Participants with drug dependence or with mental disorders within 1 year; * Participants participated in other clinical research in the last 30 days; * Any condition which would make the subject, in the opinion of the investigator or designee, not suitable for the study for any reason.