The invention relates to a planar crystal lattice type self-reconstructing robot with a three-arm butted module in the technical field of machinery, which comprises a central frame body and three butted single arms. The central frame body is an regular triangle prism, and each lateral surface of the regular triangle prism is fixedly connected with one butted single arm respectively; and each butted single arm comprises a first inner frame, a first turning motor, a middle frame, a rotating motor, a second inner frame, a second turning motor, an outer frame and a butted surface device, wherein the first inner frame is fixedly connected with a lateral surface of the central frame body, the first turning motor is fixed in the first inner frame, the rotating motor is fixed in the middle frame,an output disc of the rotating motor is connected with the second inner frame to form a second rotary motion joint, the second turning motor is fixed in the second inner frame, a driving shaft of thesecond turning motor is connected with the outer frame to form a third turning joint, and one end face of the outer frame is provided with the butted surface device. The planar crystal lattice type self-reconstructing robot has a large planar coverage factor and can achieve a plurality of deformation modes.