The performance of electrostatic precipitators (ESPs) is affected by factors such as the geometric configurations, the charge conditions and the fluid flow and the particulate flow characteristics. In this paper, a theoretical model is presented to study the particle transport in the collecting channel of a laboratory-scale single-stage multi-wire ESP. The employed model is validated by comparing its predictions with published experimental data and other theoretical prediction models. The particle size distribution is represented by a lognormal function, and the effects of the geometric parameters of ESPs on collection efficiency under different charge conditions are calculated and analyzed. The results confirm that the collection efficiency of ESPs can be enhanced by employing large-sized corona wire under the same average current density or corona power ratio, while the opposite rule is shown under the same electric field strength.