The invention discloses an adjustable packaging tape cutting machine, and relates to the field of packaging equipment. The adjustable packaging tape cutting machine comprises a workbench, the two sides of the workbench are each provided with a support rod in a vertically upward mode, an installing plate is arranged at the upper ends of the support rods, and an air cylinder is arranged on the installing plate; a movable rod is arranged on the workbench, a piston rod of the air cylinder is connected with the movable rod, the side wall of each support rod is provided with a sliding groove, the two ends of the movable rod are arranged in the sliding grooves respectively, the side wall of the movable rod is provided with a plurality of positioning holes and tool bit fixing handles, the tool bit fixing handles and the positioning holes are connected through bolts, and a cutting knife is arranged at the lower end of each tool bit fixing handle; the workbench is provided with a cutting base plate, the cutting base plate is arranged under the cutting knives, a packaging tape is arranged on the cutting base plate, the side wall of the lower end of each support rod is provided with a fixing device, and the fixing devices make contact with the packaging tape. According to the design, the structure is simple and reasonable, multiple segments can be cut at a time, the length of each cut segment can be adjusted according to different products, the cutting efficiency is high, and the cut end openings are flush.