The invention discloses a method and a device for automatically and continuously ripping packing tapes of a packing case and relates to the technical field of automatic sorting of materials. The technical scheme of the method and the device for automatically and continuously ripping the packing tapes of the packing case comprises arranging a case pushing mechanism which can apply thrust to a case body and move in one direction; arranging a guiding mechanism which can guide and limit two sides of the packing tapes of the case body; arranging a centralized positioning mechanism for determining a central position of a sealing opening of a tape and facilitating cutting of a blade extending mechanism; arranging a conveying roller to support the case body and provide conveying power. The method and the device for automatically and continuously ripping the packing tapes of the packing case improve case ripping efficiency, reduce labor intensity of an operator, have the advantages of being high in automation degree, low in fault rate and safe and reliable in operation, can be applied to logistics enterprises and have relatively high economic benefits.