The three-dimensional geometric models of conventional filter cartridge and new type one with pyramidal structure were established, and their performances of dust filtration and cleaning simulated with k-e model. The results show that the pressure difference between the inlet and outlet of conventional filter cartridge is 170 Pa, and the new filter 120 Pa under the same flow rate. The difference can be attributed to the increase of the area of new type filter cartridge with pyramidal structure and the filtration velocity is smaller than that of conventional filter, leading to the increment of filtration efficiency. The pressure peak of conventional filter cartridge along the length direction of filter cartridge increases, but the upper pressure peak is -100 Pa and the bottom pressure peak 16000 Pa. The upper pressure peak is too small and the bottom pressure peak too big, which is disadvantageous to the filter cartridge. The pressure peak of new type filter cartridge also increases along the length direction of filter cartridge changing from 3500 to 4000 Pa, the pressure peak is moderate and the distribution the pressure uniform. So the efficiency of dust-cleaning system can be significantly improved, and the service life of the filter cartridge prolonged.