Adjustable spiral girdling knife for walnut trunks

The invention discloses an adjustable spiral girdling knife for walnut trunks and relates to the technical field of forest tree cultivation devices. The adjustable spiral girdling knife comprises a handle a knife body and blades; the handle is connected to the knife body; it is characterized in that the knife body is composed of a fixed knife holder and a movable knife holder; the fixed knife holder is provided with an opening adjusting screw, a spacing groove and a connecting rod; a bottom of the movable knife holder is provided with a screw threads which are matched with the opening adjusting screw; the movable knife holder is clamped to a spacing groove and the screw threads are engage with the opening adjusting screw; the connecting rod is positioned at a bottom of the fixed knife holder and is connected with the handle; an opening is formed between the fixed knife holder and the movable knife holder inner side wall; there are two blades which are fixed on two side walls of the opening through bolts and t