Based on encrypted ball sound data, encrypted surface weather station data, ERA5 (0.25 °×0.25 °) and the Linhe New Generation Weather Radar data, A detailed analysis was conducted on the boundary layer convergence lines(BLCL )formed by the surface differences between the Hetao irrigation area and the Kubuqi Desert in the Hetao region of the Yellow River in July and August 2022 and its role in convection triggering. The results indicated that the BLCL in the Hetao area was formed by the combined influence of surface differences, boundary layer atmospheric circulation and complex terrain. And the BLCL mainly occurred at the border between the Hetao irrigation area and the Kubuqi Desert, and in a smaller arid area along the southeast bank of the Yellow River, with BLCL lengths ranging from 100 to 200 km. BLCL was a shallow system with convection heights of approximately 1000 to 1300 m. The daily variation of BLCL was significant, with a high incidence period from 12:00 to 17:00, accounting for 80%. The probability of BLCL formation in July and August of midsummer was as high as 60%, and 39% of BLCL could trigger convection. The prediction indicators about the formation of BLCL were as follows: (1) The temperature in Hangjinhouqi (53420) in Hetao Irrigation District is 2.5 ℃ lower than that in Habailaigeng (C3183) in Kubuqi Desert,and the relative humidity difference between them is up to 20% .(2) Continuous strong southerly winds was in the Kubuqi Desert and Mu Us Sandy Land areas in Hetao area, with a maximum wind speed of 10 meters above the ground greater than 4 ms ? 1^.(3) The sea level pressure field is high in the east and low in the west, and a dense isobaric zone was in the Jiziwan of Yellow River with 3-4 isobars. The formation of BLCL is of great significance to the convection triggering in this region, which is manifested in convection triggering, convection strengthening, and convection organization. Under different environmental conditions and weather system superposition configurations, the BLCL could trigger local convection, organized strong convection, torrentialSrain in Hetao area. The generation and convective triggering of BLCL in this specific region are closely related to the distribution characteristics of rapid increase in precipitation from west to east in the Hetao region.