Type Ⅵ secretion system(T6SS)is a lethal weapon that releases effectors in direct contact to kill eukaryotic predators or prokaryotic competitors.T6SS is of great significance in bacterial environmental adaptability,pathogenicity,and gene horizontal transfer.T6SS has been identified in about 25％of Gram-negative bacteria.Because of its widespread existence,T6SS is considered the key factor of ecological competition.T6SS effectors exerting biological functions have high diversity and do not have conserved sequences,and the regulatory mechanisms involved are complex.Therefore,it is a hot and difficult topic in T6SS research.Vibrio fluvialis(V.fluvialis)as a newly emerging foodborne pathogen,has unique characteristics in the quantity,composition,and physiological function of T6SS,which is related to its wide environmental adaptability and pathoge-nicity.This article mainly reviews the research progress of V.fluvialis T6SS,including its composition,structure,functional activity,and regulatory mechanism.