The invention discloses a method for promoting a flavor of a sauce, and belongs to the condiment processing technical field. The sauce is prepared through the steps of collection of a raw material salted duck egg white, dilution, degeneration, enzymolysis, enzyme deactivation, centrifugation, secondary enzymolysis, deodorization, maillard reaction, seasoning, compounding and flexible sterilization. The byproduct salted duck egg white which is not fully utilized in food processing industries is recycled and used as the raw material, the cost is saved, the environment can be protected, and important social and economic benefits are achieved; with adopting of a double-enzyme step-by-step hydrolysis way, hydrolyzed animal proteins are obtained, the hydrolysis degree is high, and obtained hydrolyzed proteins have no trichloropropanol and are safer; bitter peptides are decomposed by flavor protease, and thus a hydrolysate has no bitterness; and some unique-flavor yeasts, cooking wine and essence are also chosen, proportion of all the ingredients is reasonable, and thus the obtained product is delicious in taste and mellow in flavor.