[ Objective] The study aimed to explore the denaturalization law of β-Iactoglobulin (β-LG) under instantaneous high-pressure(IHP) con- dition. [Methed] Using fresh milk as testing material, effects of pressure, feed temperature and treatment time on the denaturalization of β-LG were studied via SDS-PAGE electrophoresis and sulfhydryl content detection after IHP treatment. [ Result] IHP could induce the agglomeration and depo- lymerization Of β-LG. The agglomeration of the β-LG increased with the elevated pressure from 20 to 60 MPa, but 80 MPa pressure led to depolyme- rization. The effect of feed temperature (25 -45 ℃) was similar to that of the pressure, while the influence of treatment time (2 -8 min) was not obvious. [ Conclusion] The study provided a theoretical basis for the elimination of allergens in β-LG and the application of IHP technology in milk treatment.