The invention relates to a waste printed circuit board non-metal powder/ABS rein composite material and its preparation method. The preparation method comprises the following steps: carrying out alcoholysis of a silane coupling agent KH-560, adding the obtained silane coupling agent KH-560 into printed circuit board non-metal powder, mixing the obtained modified printed circuit board non-metal powder, an ABS resin and a processing assistant in a high-speed mixer, putting the obtained mixture in a screw extruder, extruding, granulating through a granulator, and molding the extruded granules in an injection molding machine to prepare the waste printed circuit board non-metal powder/ABS rein composite material. The method has the advantages of reduction of the product production cost, certain economic values, recovery of the non-metal powder in a waste printed circuit board, prevention of the potential risk of the release of pollutants in randomly-stacked waste printed circuit board non-metal powder to the environment, and strong environment protection.