A fast looping-up and releasing rope loop assembly includes two one-way locking devices, at least one band, and a buckle. The one-way locking device includes a body constituted by a base and a cover. The one-way locking device allows the pull rope to extend therethrough and to move with respect thereto along a single direction. By inserting the pull rope through a rope entry opening of the base of the one-way locking device and further extending the rope around a rotary disk and a rotary wheel arranged inside the locking device and extending out of the locking device, the one-way locking device that locks the movement of the rope in an opposite direction is completed. When the rope is jammed due to excessive tightening, a presser of the buckle is depressed to release the one-way locking device from the jamming condition so that efficient loop-up and release can be realized.