Abstract: The vertical cut-off walls of slurry, such as soil-bentonite, are widely used in seepage control and retention projects for contaminated sites, especially in groundwater pollution prevention, landfills and mine tailings management. In this study, a comprehensive investigation of modern in-situ evaluation techniques and methods for vertical cut-off walls is conducted, covering a variety of evaluation means such as CPTU technology, resistivity tomography (ERT) technology and acoustic technology. The study shows that these techniques can effectively evaluate the physical and mechanical properties and impermeability of the vertical cut-off wall of slurry, thus ensuring its long-term stability and environmental safety. For the integration and innovation of different techniques, in future researches experimental devices should be further developed for coupling multiple physical processes, and the quantitative relationship should be explored between shear wave velocity and soil physico-mechanical properties. It provides a new perspective on the in-situ evaluation techniques of vertical cut-off walls for contaminated sites, which is of great scientific significance and practical value for environmental protection and pollution management.