The invention belongs to the technical field of packaging boxes, and particularly relates to a packaging box with long refrigeration time. The packaging box comprises a top cover, an outer box body, a reaction module and a storage box body. In the using process of the packaging box, firstly, freezing treatment needs to be carried out on a freezing shell, when the freezing shell designed by the invention is subjected to freezing treatment, a frozen medium in four freezing blocks flows back into the freezing shell, and then the four freezing blocks are pressed into a ball to be placed on the freezing shell, so that the space, occupied by the freezing shell during freezing, of a refrigerator is reduced, and freezing of the freezing shell is facilitated; and meanwhile, according to the designed reaction module, in the process of refrigerating articles in the storage box body, after the frozen medium in the freezing shell and the freezing blocks absorbs heat to be melted, the reaction module is triggered through the change of the volume of the frozen medium, substances, located at two sides of a partition plate, in a shell of the reaction module are in contact to generate chemical reaction, and the frozen medium in the freezing shell and the freezing blocks absorbs heat to be frozen again, so that the refrigeration time of the packaging box is prolonged.