Heat-resistant protease secreted by psychrophilic bacteria can reduce the quality of dairy products and has attracted extensive attention. The protease secreted by psychrophiles is heat resistant and can even retain partial activity after UHT treatment. The common exogenous thermostable protease in raw milk is the extracellular protease AprX secreted by Pseudomonas， so a comprehensive understanding of the biological properties， proteolytic potential and regulation of the protease AprX will help to find ways to control psychrophilic protease. In this paper， the latest research progress and control methods of protease AprX are reviewed， and new ideas for the control of protease AprX are provided.