The invention relates to a double-cartridge filter. The double-cartridge filter comprises a top cover, a purification chamber, a dust removal chamber and an ash hopper, wherein an air inlet pipe is mounted on the side wall of the dust removal chamber, and an air outlet pipe is mounted on the side wall of the purification chamber; the purification chamber and the dust removal chamber are isolated by a porous plate; cartridges are mounted at pores of the porous plate, upper ends of the cartridges are sealed and fixed with the pores of the porous plate, and the lower ends are fixed on a support reticular plate; the support reticular plate is fixed between the dust removal chamber and the ash hopper; an electrostatic generator is further mounted outside the dust removal chamber and comprises a reversing switch; electrostatic tubes are coaxially arranged in the cartridges, and lower ends of the electrostatic tubes are mounted on the support reticular plate; the electrostatic tubes are electrically connected with the electrostatic generator. The double-cartridge filter can promote dust to be attached to the cartridges rapidly, realizes efficient dust removal and can clean ash simply and rapidly.