Abstract: From 2013 to 2017, lightning data from WWLLN (Worldwide Lightning Location Network) was combined with ERA-5 (the fifth-generation reanalysis data from the European Centre for Medium-Range Weather Forecasts) to study lightning activity across different regions of Chinese mainland. The research analyzed the relationship between lightning and meteorological factors, including CAPE (convective available potential energy), precipitation (P), CIN (convective inhibition), and RH (relative humidity), focusing on spatial and temporal distributions and their quantitative correlations. The results indicate that lightning has a good correlation with CAPE, P, and CAPE×P in time and space. Lightning activity is most likely to occur when CIN is appropriately small and CAPE is sufficiently high. Higher CAPE values generally lead to increased lightning activity, while smaller inhibition energy promotes convection, thereby increasing the likelihood of lightning. However, CIN should not be too small, as excessively low CIN values result in reduced lightning activity. A low CIN value alone is not sufficient for lightning; a high RH is also required. The study found that lightning activity typically occurs in environments with RH levels between 60% and 90%. If RH continues to increase beyond this range, lightning activity will decrease. Even under high CIN conditions, significant lightning activity can still occur if both moisture and CAPE conditions are favorable.