The invention provides a light-weight, energy-saving and environment-friendly prefabricated floor slab. The floor slab comprises a plurality of bamboo layers and concrete layers by which the bamboo layers are wrapped, bamboo rods between two adjacent bamboo layers are vertical to each other, bamboo stirrups are fixed on two sides of each bamboo rod which is arranged at the even-numbered bamboo layer, and the bamboo stirrups encircle each bamboo rod which directly faces the odd-numbered bamboo layer in the vertical direction; the concrete layers which are arranged on the left or/and right side(s) of the prefabricated floor slab are provided with first horizontal connective grooves from beginning to end along the length direction of the bamboo rods on the odd-numbered bamboo layers, and the concrete layers on the bottom surface of the prefabricated slab, which are 10-40cm away from the front and rear end faces of the prefabricated slab, are provided with second horizontal connective grooves from beginning to end along the length direction of the bamboo rods on the even-numbered bamboo layers; and the first horizontal connective grooves are connected with vertical material injecting grooves, and the tops of the second horizontal connective grooves are connected with vertical material injecting pipes. According to the prefabricated floor slab provided by the invention, the hollow structures of the bamboo rods are utilized to enable the floor slab to have the effects of light weight, thermal insulation, sound insulation and shock resistance, and connective columns can be formed at joints not only between slabs but also between a slab and a beam through the grooves arranged in the end face and bottom surface of the prefabricated floor slab and matching with a concrete grouting pump.