为解决深基坑地下连续墙施工过程中经常出现的槽壁垂直度难以控制、槽壁坍塌风险高以及槽底沉渣难以清除等问题，综合运用室内试验、现场实测等技术手段，着重对超深圆形地下连续墙施工过程中基槽开挖、泥浆控制、钢筋笼施工三个方面的关键技术进行阐述，得到了以下结论：（1）泥浆比重随开挖深度增加逐渐增大，黏度在开挖过程中变化不大，含砂率在开挖过程中随地层的变化而变化；（2）在施工中成槽速度应遵循以下变化规律：上部黏土层（正常）→中部含砾石黏土层（较慢）→下部黏土层（慢）→底部岩层（最慢）；（3）钢筋笼吊装时，采用等强剥肋滚压直螺纹对接两节钢筋笼，实际有效连接率达到95%以上，连接效果好。

In order to solve the problems frequently encountered in the construction process of diaphragm wall of deep foundation fit, including the difficulty in controlling the verticality of the trench wall, the high collapse risk of the trench wall and the difficulty in removing the sediment at the bottom of the trench, etc., the laboratory test and on- site measurement were used comprehensively to study the three key technologies related to the construction of ultra-deep round diaphragm wall, i.e. the excavation of foundation trench, the control of mud parameters and the construction of steel cage. Accordingly, the following conclusions can be drawn: (1) the specific gravity of the mud increases gradually with the deepening of excavation, the viscosity does not change much during the excavation process, while the sand ratio of the mud varies according with the change of stratum; (2) during the process of excavating trench, the speed of excavating should follow the law as fellows: upper clay layer (normal)→middle clay layer containing gravel (slow)→ lower clay layer (slower)→ bottom rock formation(slowest); (3) during the process of haisting steel cages, two steel cages were connected by the equal- strength stripping rib rolling straight thread, the actual effective connection rate is over 95%, and the connection effect is good.