Using whey protein as raw material and treated with high hydrostatic pressure technology， the effect of different pressures on the structure and properties of whey protein was studied. The results showed that the treated whey protein changed from the original hollow spherical structure to a honeycomb porous ordered structure. At 300 MPa， the average particle size (34.87 μm) and the absolute value of zeta potential (-211.57 mV) are minimal. The random was converted into β-turn， the β-turn content increased from 24.63% to 39.97%， and the random content decreased significantly from 30.67% to 15.60%. The free sulfhydryl content decreased， and the disulfide bond content increased from 1.69 μmol/g to 3.82 μmol/g. Fluorescence spectroscopy showed that whey protein had the best hydrophobicity at 400 MPa. Moreover， the processing characteristics of whey protein after high hydrostatic pressure treatment such as foaming， emulsification， water/oil holding capacity and oxidation resistance have been significantly improved. The foaming ability and emulsifying ability of whey protein reached the best value at 400 MPa， the foaming ability reached up to 40.67%， the emulsifying reached up to 108.4 m2/g， the water/oil holding capacity increased by 83.50%/144.52%， and the free radical scavenging capacity increased from 7.64% to 14.15%. This study provides a reference for the development and property of whey protein products with high hydrostatic pressure technology.