The invention discloses a biomarker for predicting severe treatment of a COVID-19 patient and application of the biomarker, and relates to the technical field of
biomedicine. According to the invention, a COVID-19 patient severity prediction or auxiliary prediction model which is obtained by constructing biomarkers including Gemelia haemolsos,
Streptococcus sp.A12,
Fusobacterium pseudoperiodontium, Gemelia mollissima, Villonella atypical, Villonella rogosa and
Prevotella melaninogena is found, the model is used for predicting and evaluating the severity of the COVID-19 patient, the sensitivity is high, and the specificity is good. The invention further discloses a method for predicting and evaluating the severity of the COVID-19 patient severity, and the method has the advantages that the method can be used for predicting and evaluating the severity of the COVID-19 patient severity;