The invention discloses a method for improving the solubility of potato protein by combining ultrasound with pH offset, and belongs to the technical field of protein modification. The method comprisesthe following steps: (1) peeling potatoes, dicing the peeled potatoes, and soaking the diced potatoes in a 0.12% sodium sulfite solution; (2) homogenizing the potatoes and standing for 15 minutes, centrifuging, taking a supernatant, regulating the pH value to 8.0, stirring and extracting at room temperature for 2 hours, centrifuging, taking a supernatant, regulating the pH value to 4.0, standingfor 1 hour, taking a precipitate, adding distilled water, redissolving, regulating the pH value to 7.0, and freeze-drying to obtain potato powder; (3) preparing a proper concentration of the obtainedpotato protein, and carrying out ultrasonic treatment; and (4) adjusting the pH value of the protein solution subjected to ultrasonic treatment in the step (3) to 12.0, maintaining the pH value for 1hour, and adjusting the pH value to 7.0 to obtain a modified potato protein solution. The modification method provided by the invention can greatly improve the solubility of the potato protein, and has very important significance for expanding the application field of the potato protein.