Abstract:Psychrophilic bacteria are a general term for a class of microorganisms that can grow normally under low temperature conditions.The unique living environment of psychrotrophic bacteria is attributed to its unique psychrophilic mechanism，and its unique psychrophilic mechanism depends on the physiological functions played by its own unique physiological structure.These unique physiological structures allow psychrotrophic bacteria to grow normally under low temperature conditions，and also provide us with a large number of biological resources that are still active under low temperature conditions.This article explained the psychrophilic mechanism of psychrophilic bacteria from the aspects of cell membrane fluidity regulation，antifreeze protein，cold shock protein and cold active enzyme，introduced the functional components of the psychrophilic mechanism，described the principle of the psychrophilic mechanism and analyzed the application prospects of the unique biological characteristics of psychrotrophic bacteria in the field of food.