The invention discloses an application of chrysin to preparation of medicines for treating methicillin-resistant staphylococcus aureus infectious pneumonia. The chrysin is also called chrysin, the chemical formula is C15H10O4, the chemical name is 5,7-hydrogen flavone and 5,7-dihydroxyflavone, and the chrysin is a flavonoid compound which is obtained through separation from bignoniaceae plant semen oroxyli and has extensive pharmacological activity. Pharmacological medicine research indicates that the chrysin has various pharmacological activity such as effects of resisting blood fat, resisting inflammation, resisting atherosclerosis and the like. The chrysin can be applied to preparation of medicines for treating the methicillin-resistant staphylococcus aureus infectious pneumonia, and has better protection effects on the methicillin-resistant staphylococcus aureus infectious pneumonia. The application disclosed by the invention has the beneficial effects that through human pulmonaryepithelial cell invasion experiment and a mouse staphylococcus aureus pneumonia model, the situation that the chrysin has protection effects on staphylococcus aureus infectious pneumonia is confirmed.