Fully-prefabricated floor slab and fully-prefabricated floor slab connecting joint

The fully-prefabricated floor slab comprises a floor slab body, shear-resistant key grooves are formed in the end face of the floor slab body at intervals, the shear-resistant key grooves are recessed towards the interior of the floor slab body, the exteriors of the shear-resistant key grooves are open, and horizontal reinforcing bars exposed out of the floor slab body are arranged on the end face where the shear-resistant key grooves are located at intervals. The horizontal reinforcing bars are of closed U-shaped structures, bolt holes are formed in the thickness direction of the floor slab body and penetrate through inner cavities of the shear-resistant key grooves, and sleeves are embedded in the inner walls, opposite to the bolt holes, in the shear-resistant key grooves. When the floor slabs are connected, the horizontal reinforcing bars at the ends of the two fully prefabricated floor slabs are overlapped in a staggered mode, the shear-resistant steel plates are inserted into the shear-resistant key groo