The invention discloses an oil tank cleaning device, which aims to solve the shortcomings of low working efficiency, big labor intensity, existence of safety hidden trouble, poor derusting effect and heavy dust in derusting process of the derusting cleaning operation of the oil tank. The oil tank cleaning device comprises a bracket, wherein the lower end of the bracket is equipped with several driving wheels, and a magnetic absorbing block is installed on the bracket; the lower part of the bracket is provided with two arc elastic track rods arranged at equal space; a bottom plate is moveably connected to the middle of two elastic track rods along the elastic track rods, and the lower part of the bottom part is equipped with a brush disk, and the edge of the lower surface of the brush disk is equipped with several painting heads; a dust collector and an annular dust collecting cover are connected to the bottom plate; the dust collecting cover closes to the edge of the brushing disk; the dust collecting cover is connected with several dust collecting pipes connected to the dust collector.