The invention provides a file replacing method and device. The method comprises the following steps: independently loading a source portable document format file which is selected by a user and needs to be replaced and a target backup database adopted during replacement; outputting a first human-computer interaction interface which displays a source leaflet name list and a backup leaflet name list, wherein the source leaflet name list comprises the names of all leaflets contained in the source portable document format file and the names of all leaflets contained in the target backup database; according to the selection of the user in the source leaflet name list and the backup leaflet name list, determining a source leaflet which needs to be replaced in the source portable document format file, an assigned backup leaflet in the target backup database and a corresponding replacement relationship between the source leaflet which needs to be replaced and the assigned backup leaflet; and according to the corresponding replacement relationship, replacing the source leaflet which needs to be replaced with the assigned backup leaflet. The file replacing method and device solves the defect of low efficiency when the portable document format files among different editions are replaced.