The invention discloses a disk counting device for a disk grabber. The disk counting device comprises a support body, a sensing component and a moving component, wherein the lower end of the support body is fixed on the support of the disk grabber; the sensing component is fixed on the support body and used for sensing the displacement of the moving component; the moving component is capable of moving upwards relative to the sensing component when the lower end is stressed by an upward action force. The invention further discloses a disk grabber with the disk counting device, and a disk counting method of the disk grabber. The disk grabber drives an insertion portion to move downwards from the central hole of an optical disk, meanwhile, the moving component contacts with the upper surface of the optical disk and is extruded by the optical disk to move upwards relative to the sensing component, and the depth of the insertion portion entering the central hole of the optical disk and the corresponding number of the optical disks through sensing the relative positions of the moving component and the sensing component. The disk grabber disclosed by the invention is accurately used with the disk counting device, thus the working efficiency and automation degree of the disk grabber are improved while the operation faults of the disk grabber are reduced.