The invention discloses a self-propelled trolley conveying line polling device. The device comprises an auxiliary beam and a rail; and the rail is mounted on the auxiliary beam. The device is characterized by further comprising a polling trolley; the polling trolley includes a transparent cover, a main trolley, a secondary trolley, a balance beam, a laser anti-collision sensor, a temperature sensor, a sensor bracket, a combustible gas sensor, a camera, a control center, a signal wire, two balance beam stabilizing devices and two trolley body stabilizing devices; each balance beam stabilizing device includes a guide rod, a nut, a guide sleeve, a large compression spring, a roller base, a roller rotating shaft and a roller; the guide sleeve is mounted in a hole of the balance beam; the roller is mounted on the roller base through the roller rotating shaft; the upper end of the guide rod is welded on the bottom surface of the roller base; and the compression spring coats the guide rod, and is mounted between the bottom surface of the roller base and the upper end surface of the guide sleeve. The device is novel in structure, excellent in polling effect, safe, reliable, low in labor intensity and capable of prominently improving the labor conditions.