-In this paper, a space and time domain finite volume method is proposed to study the characteristics of space charges on a bar-to-plate geometry. Three ionic species, namely, positive ions, negative ions, and electrons, are considered. A finite element method is used to solve Poisson's equation, and a finite volume method is used to solve charge transport equation. Different time steps based on space domain and time domain are applied to improve computational efficiency when solving the charge transport equation. Four points are marked to indicate the characteristics of a Trichel pulse. Density distributions of three ionic species and electrical field strength along the axis are presented. Trichel pulses on a bar-to-plate geometry are simulated and compared with the experimental results. Good agreements are obtained, thereby confirming the validity of the proposed method.