Abstract:Combined with the construction of Huarong Meitian Lake Bridge in Dongting Lake Area, the hole-forming technique of large diameter rotary digging drill with efficient stabilizing fluid in silt deep hole is analyzed, studied, applied and practiced. The technical indexes and measures are put forward in detail. The efficient stabilizing fluid applied in the large-diameter rotary digging pore-forming technique of soft soil and deep hole has the characteristics of fast hole-forming speed, good engineering quality and remarkable integrated benefit, which can be referred for the hole-forming construction of pile foundation under the similar geological conditions.