中文摘要：

Based on the monitoring data of cloud-to-ground (C G ) lightning positioning network and Doppler weather radar as well as MICAPS1° x1° objective analysis field, a squall line process outside of the subtropical high in low-latitude plateau on May 7, 2010 was analyzed. The results showed that wind direction shear between low and high levels and low-level convergence zones provided favorable circulation background for the strong thunderstorm process, while high energy and high humidity, strong thermal instability and ascending motion at low and middle levels offered beneficial environmental conditions for the formation of the thunderstorm. 9 620 return strokes of cloud-to-ground lightning were monitored by the lightning positioning network, and cloud-to-ground lightning was distributed like bands between 584 and 586 hPa. The occurrence of cloud-to-ground lightning was mainly related to echo top and echo intensity at -10℃ stratification height, and it mainly appeared in zones where echo top height was larger than 13 km and echo intensity at -10℃ stratification height was 35 -40 dBZ. Wind convergence and maintaining of high radial velocity were favorable for the development of convective echoes and occurrence of cloud-to-ground lightning.