Abstract: Pseudospark discharge is a special kind of low pressure discharge which is ignited in hollow cathode, and the main discharge channel presents diffused characteristics. It is widely applied in pulsed discharge switch and electron beam sources. In this paper, to study the initial process of pseudospark discharge, a two-dimensional electrostatic plasma simulation model is built based on particle in cell and Monte Carlo collision method (PIC/MCC), which is coupled with external circuit elements. By studying the evolution of electrons, ions and electric potential, a series of sub-phases are distinguished, including trigger electron propagation, Townsend discharge, virtual anode formation and penetration, hollow cathode discharge, formation of potential hump, ion depletion, etc., and it is confirmed that electrons which reach anode consist of high energy and low energy components. In addition, the effects of gas pressure and initial electrons on trigger delay and peak value of anode electron current are studied. The simulation results show that all parameters affect the trigger delay and peak value of electron current, respectively, through the ion density near cathode aperture and the electron density inside the cathode cavity. As the gas pressure, charge amount, electron energy, injection time, and the forward movement of trigger position increase, the trigger delay can be shortened. However, as the electron energy and the forward movement of the trigger position increase, the peak value of electron current may decrease but show a saturation trend. Finally, the possible relationship between ion depletion near cathode aperture and current quenching at hollow cathode phase, as well as the influence of external circuit inductance and PIC method on the simulation results are discussed.