泥水盾构在掘进过程中，由于受到环境条件有限、地质条件差、水土压力高、地层复杂多变等多种因素的影响，如何安全高效地更换滚刀和齿刀一直是盾构施工所面临的工程难题。本文提出一种高水土压力条件下滚刀、齿刀常压更换技术，介绍该技术的工作原理和作业要点，并以武汉地铁8号线越江隧道工程为例，针对越江隧道江中段的上软下岩复合地层以及工程所面临的特有工程难点，详细阐述滚刀、齿刀常压更换技术的具体操作步骤及其技术优势。通过采用该技术，有效提高了换刀效率，降低了安全风险，确保了施工的顺利进行。

During tunneling, the slurry shield is often disturbed by many factors, i.e. limited environmental conditions, poor geological conditions, high soil and water pressure, complex and variable strata, etc. How to replace the disc cutter and gear cutter safely and efficiently has always been a problem for shield tunneling. To improve the safety and efficiency replacement of disc cutter and gear cutter of slurry shield, a method of replacing disc cutter and gear cutter under atmospheric pressure with high soil and water pressure is proposed. And then the working principle and main points of the technology are introduced; and the technology is applied to rivercrossing tunnel on Wuhan Metro Line No. 8. Finally, the detailed operation procedure and the superiorities of disc cutter and gear cutter replacement technology under atmospheric pressure are introduced according to characteristics of the uppersoft and lowerhard composite strata and project difficulties. By adopting the abovementioned technology, the cutter replacement efficiency has been improved, the construction safety risk has been reduced and the successful tunneling has been guaranteed.