Abstract: Numerical simulation are performed on the the flow field, electric field and charged particle trajectory in electrical area of EBP by using FLUENT software to work out the minimum removal diameter of dust in electric field and optimize the opening range of dust collector. Electric distribution and flow field distribution are numerically simulated. The particle movement and velocity distribution in the voltage of 45 kV in electric field, whose diameter includes 0.5, 1.5 and 2.5 μm, are numerically simulated and analyzed. The results show that the minimum removal diameter is 1.5 μm and the optimal opening ranges from 0.324 m to 1.25 m along the X direction in electrical passageway. The results can be used as theoretical reference for both electrostatic fabric filter design and structure optimization.