Method for preparing sterile liquid by virtue of ultra-high pressure technique and milk product prepared by virtue of method

The invention relates to a method for preparing sterile liquid by virtue of an ultra-high pressure technique and a milk product prepared by virtue of the method. The method comprises the steps of carrying out ultra-high pressure treatment on a water solution containing effective constituents, wherein the ultra-high pressure treatment comprises the step of carrying out alternation pressurization on the water solution containing the effective constituents, wherein the number of alternation pressurization is 0-5, the pressurization pressure is 300MPa-1000MPa, the total pressurization time length is 2-80 minutes, and the temperature is 0-80 DEG C; the effective constituents comprise lactase, lactoferrin, immune globulin, milk basic protein or active peptide, and the activities of lactase, lactoferrin, active peptide, immune globulin and milk basic protein in the sterile liquid can be still maintained after the ultra-high pressure treatment. The invention provides a milk product. The milk product contains active lactase, lactoferrin, immune globulin, active peptide milk or basic protein.