Abstract: Based on the analysis of the tension erection construction scheme of the guide ground for the ±800kV/500 kV AC-DC mixed tower erection in the Chizhou Yangtze River large span section of ultra high voltage（UHV） Baizhe Line project, combined with the performance of the scheme in the actual construction, the main ways and means to improve the construction efficiency of the large span closure overhead line are discussed.This is the first UHV large-span project that adopts ±800 kV single-loop DC and 500 kV double-loop AC mixed-voltage design in China. The span distance is 2 354 m, and there are 38 guide ground wires in the file.The construction scale is unusual, and conventional methods can not meet the construction needs. After a comparative study of the schemes, combined with the actual engineering, the overall pay-off construction technology of 2ד2 pull 3” and 4ד1 pull 1” is adopted for ±800 kV DC and 500 kV AC respectively, and the setting of pay-off block, the selection of stretching equipment and the layout of the site, the configuration of traction ropes and boats are improved and optimized. The number of times of sealing-off and construction period are reduced effectively,and the requirements of the project are met. After the actual engineering verification, on the basis of ensuring the quality of the project, all the construction tasks have been completed according to the requirements of the construction period. This technology is of great significance to improve the overall efficiency of large span line erection.