With nonwovens production line going for large-scale, high-speed and high efficiency, the nonwovens roll goods tend to be off-line with full width and no cutting and slitting, thus off-line slitter has been a significant part for the production line. Main function and application of off-line slitter were introduced in this paper, as well as technology development status quo. Besides, the structure and control system of this kind of device were stated in detail.