The non-inductive charging mechanism and simple discharging parameterization scheme were coupled to Morrison microphysical scheme in WRF model, and the Lightning Potential Index (LPI) was introduced to the model, on these bases, a squall line occurred in North China on June 16, 2009 was simulated, in order to determine the reappearance ability of the lightning flash density by the proposed model. Results show that the model can quite better recreate the observed radar echo and precipitation distribution features, therefore, it is able to simulate the macroscopical and electrical features of this squall line. The calculation of indirect simulation of LPI represents roughly the lightning distribution feature, but the LPI distribution covers obviously the wider range than the observed lightning distribution. The direct simulated lightning density reproduces the observed lightning distribution reasonably. Due to the total lightning density given in model output, it is nature to find larger C-G lightning density than the observed one.