Abstract: Due to the limited coverage of three-dimensional lightning detection networks, research on the total lightning characteristics of supercells that produce tornadoes and hail remains insufficient in China. A supercell generating a severe tornado and hailstones exceeding 10 cm in diameter in Guangdong Province on 27 April 2024 is analyzed, utilizing dual-polarization radar data, Guangdong-Hong Kong-Macao Lightning Location Data, and three-dimensional lightning mapping data from the low-frequency E-field detection array (LFEDA). Results indicate that the mesocyclone within the supercell persists for 4.5 h, with 16067 total lightning flashes and a peak flash rate of 610 flashes per 6 min. Intra-cloud flashes account for the majority of lightning activity (92.30%), and there are significant positive correlations between fluctuations in graupel volume above the melting layer and total lightning flash rates (r=0.85, p<0.05). Prior to the formation of a tornado, rapid reductions in mesocyclone height and horizontal scale are observed, accompanied by an increased proportion of positive cloud-to-ground lightning flashes (51.73%). The lower boundary of the high-density lightning radiation source region (no less than 60 km^-1·(6 min)^-1) descends from 4.2 km to 2.0 km. During the tornadic phase, the lightning hole (a region characterized by minimal lightning initiation or propagation) emerges simultaneously with the tornado touchdown and corresponds to the area of strong updraft. The lightning-active zone (defined as lightning extent density no less than 20 km^-2) is located north of the lightning hole. Post-tornadogenesis, total lightning activity intensifies significantly, with higher peak flash rates and an upward shift of approximately 1 km in the upper boundary of the high-density lightning source region, while the proportion of cloud-to-ground lightning decreased. Microphysical analysis reveals that the vertically integrated liquid water content experiences a rapid increase, with a 126-min interval observed between this increase and the initial occurrence of hail hitting the ground. The average height of initial lightning radiation sources is 9.42 km, which corresponds to a temperature of -25 ℃ level. During hail events, the spatial distribution of the flash convex hull area and lightning extent density is relatively low within the hail accumulation zone at -25 ℃ level. The hail core is situated to the south of the lightning-active zone, whereas the hail impact locations are found on the west side of this lightning-active zone.