Abstract: Based on the data of Atmospheric Electric Fieldin in Sichuan Province from 2009 to 2019, the variation characteristics of ground electric field during lightning activities in plains and plateaus of Sichuan Province are analyzed. The results show that the duration of lightning process in plain area is 30~350min, and the average duration is 158min. According to the change trend of ground electric field, it is divided into two categories: the ground electric field value is mainly negative dipole charge structure, and the ground electric field value is from positive to negative tripolar charge structure. The charge accumulation speed of thunderstorm cloud in plateau area is fast, and the breakdown of air occurs early. The time for lightning process to develop to the vigorous stage is short. The duration of lightning process is 30~360min, and the average duration is about 93min.The classification is consistent with that in plain area.