The invention relates to the dry food processing engineering field, and in particular, relates to a preparation process of a high-emulsifiability egg yolk powder. An egg yolk liquid has the pH adjusted for two times in an egg yolk powder preparation process, after first-time pH adjustment, the temperature is increased by heating to make proteins in the egg yolk liquid generate network charges having a rejection or dimerization effect for changing a protein surface layer structure, so that the effect of improving the emulsifiability of the egg yolk powder is achieved. After the egg yolk liquid is cooled to room temperature, the pH is adjusted for the second time to neutral, so the egg yolk powder can maintain a relatively stable state, the obtained product can withstand harsh conditions, the same texture, taste, stability, flavor intensity and rheological properties can be achieved with use of less amount, the cost is saved, and the productive benefits are increased.