Based on the site error model for optimizing the lightning location data, about 200 lightning flash samples in Pingliang, Gansu Province are corrected and compared with the radar echoes of over 35 dBz at the corresponding cloud top height of over 7 km. The results show that the uncorrected CG (CloudtoGround lightning flashes) locations are tens of kilometers apart from the radar echo area, and the corrected CG lightning locations are very close to the strong radar echo area. The results also show that the residual errors between the corrected and real flash directions are less than 0.5° after correcting. The site errors of the lightning location system can be minimized by this optimizing model, and this parameterization method of the site errors estimation is very important for the development of nowcasting lightning forecast.