The invention discloses a rotating anode electrostatic precipitator, comprising a rotating anode device, a cathode ray and a rotary steel brush ash-cleaning mechanism, the rotating anode device comprises a drive roller, a driven roller, a drive sprocket which connects the drive roller and the driven roller, a drive chain and an anode plate which is connected on the drive chain, the heteropolar distance between the anode plate and the cathode ray is 200mm or 230mm or 260mm; the driven roller adopts a free suspension structure and can ensure the automatic centering of the driven roller and the free tightening of the drive chain; the rotary steel brush ash-cleaning mechanism comprises at least one pair of ash-cleaning brush components which rotate reversely, the central distance of each pairof the ash-cleaning brush components which rotate reversely is continuously adjustable, and movable sealing devices are arranged at two ends of each ash-cleaning brush component. The rotating anode electrostatic precipitator simultaneously takes into account of secondary blowing dust, dust-removing effect, occupied area and equipment cost. An electric field can operate efficiently and stably, thecost and the equipment load are reduced, and the service life is simultaneously prolonged.