A spiral cutting device includes a blade, a blade driving shaft, a guiding device, a driving device, and a controller. The blade is for processing a roller. The blade driving shaft drives the blade to move toward the roller. The guiding device moves in a guiding direction perpendicular to a moving direction of the blade. The driving device is movably supported on the guiding device and rotates the roller. The controller controls a feeding amount of the blade, a moving speed of the driving device, and a rotate speed of the roller to spirally cut the roller. When an outer surface of the roller is unfolded to a plane, the blade path of the blade is in sinusoidal shape or in cosinusoidal shape.