The invention relates to a handheld oppositely-folded labeling machine and a use method. The handheld oppositely-folded labeling machine comprises an upper caliper body, a lower caliper body, clamps, first drive wheels, second drive wheels, a label storage box, label guiding channels and a sensor. The upper caliper body and the lower caliper body are movably hinged, the front end of the upper caliper body and the front end of the lower caliper body form a clamping opening, and the inner diameter of the clamping opening is matched with the outer diameter of an optical cable; the rear end of the upper caliper body and the rear end of the lower caliper body are both provided with handles; the front end of the upper caliper body and the front end of the lower caliper body are internally provided with the label guiding channels, the upper caliper body is internally provided with the label storage box, an output opening of the label storage box communicates with the label guiding channels, and the clamps, the first drive wheels and the second drive wheels are arranged in sequence from the output opening of the label storage box to the clamping opening; the sensor is fixed to the lower caliper body; and the lower caliper body is provided with a leading-out opening. The handheld oppositely-folded labeling machine has the advantages that the handheld oppositely-folded labeling machine is simple in structure and simple, light and portable as a whole, the front ends of the caliper bodies can be stretched into a narrow space to perform labeling operation, and labels can be oppositely folded and pasted neatly and efficiently.