Filtration is one of the most effective methods to remove suspended fine particles from air. In filtration processes, pressure drop of compact dust cake causes problems in efficiency and economy, which has received increasing attention and still remains challenging. In this study, we developed a novel technique to intensify the filtration of fine particles with efficient humidification. Two strategies for humidification, including ultrasonic atomization and steam humidification (controlling of ambient humidity), were employed and proved to be both effective. The regeneration frequency of the filter could be reduced by 55% with ultrasonic atomization, while steam humidification could lead to a 78% reduction in regeneration frequency. The effect of operating conditions on pressure drop and the mass loading during filtration were investigated. The dust cake showed a loose and porous structure with an optimized droplet-to-particle ratio. With the ratio of 1.53 and 0.0282, the maximum mass loading was 552 g.m(-2) upon the ultrasonic atomization and 720 g.m(-2) upon the steam humidification. The results show that humidification could slow down the increase of pressure drop during filtration and improve the efficiency of process. (C) 2015 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.