The invention relates to a method for prolonging the expiration date of bean curd and belongs to foods and the technical field of food processing. The method is a physical preservation method harmless to the texture of the bean curd and comprises the steps of putting the prepared fresh bean curd into a sterile box, pouring yellow seriflux into the sterile box until exactly submerging the bean curd, and sealing the sterile box by utilizing a polyvinyl plastic film. The method is a preservation technique harmless to the texture of the bean curd and has the beneficial effects that no preservative is added, the requirement of people on pursuing greed foods is met, and the disadvantages that the texture of the bean curd is changed, and the taste of the bean curd is declined when the bean curd preserved by utilizing existing physical methods are overcome.