The utility model provides a heat coding machine, and belongs to the technical field of machinery. The heat coding machine solves problems that an existing heat coding machine is not reasonable in structure design, and takes a large floor area. The heat coding machine comprises a mainboard and a print head on the mainboard. An unreeling wheel and a rolling wheel used for strip winding are disposed a same side with the print head on the mainboard. The mainboard is also provided with a stepping wheel and a pinch roller driven by a motor. The stepping wheel and the pinch roller are abutted against each other. The unreeling wheel, the print head, the stepping wheel, and the rolling wheel distribute along a strip winding direction. The mainboard is also provided with a guide bar. The heat coding machine is advantaged by compact structure, reasonable design, etc.