The invention discloses a high-efficiency ground slotting device. The device comprises a vehicle body; rolling wheels are arranged at the bottom of the vehicle body; a mobile rack is arranged in the vehicle body, the lower part of the mobile rack is fixedly connected with a crossbeam plate, and the right side of the crossbeam plate is in rotating connection with a grinding wheel; and a dust sucking cylinder is arranged between the grinding wheel and a slotting blade group. Slotting blades connected in an interlaced manner are arranged to crush concrete, so concrete slag can be conveniently collected; an industrial dust suction machine, a dust sucking cylinder and an outer guiding block are arranged to fully suck the concrete slag; and the grinding wheel is arranged to polish the inner wall of a groove body to make the slag fully crushed and sucked and guarantee the parallel and level of edges of the groove body, so a pipeline can be conveniently directly laid, the groove body can be molded once, and the slotting working efficiency is improved.