On the basis of MC-I spec, the square spec pulse dust filter with cloth bag MC-II is the amended and improved one. In addition to the advantages that I spec is high in the dust removing efficiency, big in the air capacity, stable in the performance, easy in operation and maintenance, MC-II has the better result than MC-I. Such as: it is not easy to build up the powder and its application is wide and so on. The device is widely used for the ventilation, dust removing and powder restoration in the grain, food, feed, metallurgical, chemical, building material, medical and other industries.