This variable cutoff folding device 100 comprises: a cutting mechanism 10 capable of changing a cutting length; a speed-increasing conveyor mechanism 20 capable of changing a conveying speed based on a change in the cutting length; a folding cylinder 40 having a pin device 41 and a thrust blade device 43, the thrust blade device 43 being configured to be displaced based on the change in the cutting length; and a jaw cylinder 50 configured to be rotationally displaced based on displacement of the thrust blade device 43.