In this paper, we investigated the relationship of filter efficiency and pressure drop with the porosity, fiber diameter and filter thickness by 3-D simulation. It was found that filter efficiency increased when the filter porosity and fiber diameter decreasing or filter thickness increasing. The pressure drop values had a linear relationship with filter thickness, and non-linear relationship with filter porosity and fiber diameter. Compared to the actual test results by Mercury Intrusion Porosimeter, the simulation results could be used for predicting filter efficiency and pressure drop within acceptable tolerance limit.