The invention discloses a wall crawling device. The crawling device can be sucked on planar walls by the aid of suckers. The wall crawling device has the advantages that the wall crawling device can crawl on the walls by the aid of two groups of suckers; supports of the two groups of suckers are connected with shaft sleeves by shafts, the two supports can rotate relatively, and the shafts are perpendicular to the walls when the crawling device is sucked on the walls; the shafts and the shaft sleeves of the two supports also can move relatively in the axial directions, so that the two groups of suckers sucked on the walls can be respectively lifted from the walls to be separated from the walls or can be laid down to be close to the walls; one of the sucker supports can be divided into two portions, namely, a combination of support bodies and a combination of support legs, the support bodies are connected to the other group of suckers, the support legs are connected with the various suckers of the corresponding group, and the support bodies and the support legs can move relatively in perpendicular planes of the shafts; a relaxed safety rope is connected with the crawling device, and the crawling device can be protected by the safety rope when crawling on the walls, can be instantly pulled by the safety rope once the crawling device falls off from the walls and accordingly can be prevented from dropping.