The invention relates to a polyamine derivative medicinal salt and preparation method and use in preparation of a drug for treating pyemia. The novel compound has good antagonistic action on a plurality of pyemia-causing pathogen-related molecules such as bacterial lipopolysaccharide (endotoxin), bacterial genome DNA, peptidoglycan, teichoic acid, virus RNA, and zymosan, and can be used for preparation of a drug for treating pyemia.