Pulsed plasma thruster（PPT） is a promising electric propulsion device with simple structure and high specific impulse

and it can be used for attitude control and position keeping of micro-satellite. The electrical parameters（resistance and inductance） of the discharge circuit of PPT can provide a reference for the optimization of PPT performance.We employed the Segmentation Formula Fitting Method to calculate the electrical parameters.The primary discharge is divided into two parts for calculation. The experimental data can be made full use of and the range of electrical parameters in the process of discharge can be calculated by the method compared with the eigenvalue method. The results show that the resistance increases and the inductance decreases during the discharge

and the electrical parameters are related to the discharge voltage. The resistance increases with the decrease of the initial voltage

but the inductance hardly changes.For plasma energy distribution

the changing plasma parameters mainly affect the magnetic energy in the early stage of discharge and the deposition energy in the final stage of discharge.