The diaphragm wall technology originated in Europe. It was developed by applying the bentonite slurry wall-protection and underwater concrete placement techniques used in shaft sinking and oil drilling to engineering projects. It was formally applied in a project in Milan, Italy in 1950, introduced to Japan in 1959, and during the same period applied in seepage cutoff walls for dams in water conservancy projects in China. Since the 1970s, it has been used in building engineering, and in recent years it has become very common in underground and other projects. The main trenching machinery for diaphragm wall construction includes the grab trenching machine, the percussion trenching equipment, the hydraulic trench cutter, and the multi-head drill trenching machine.

　　1 Grab trenching machine
　　Features: simple structure, easy to operate and maintain, low operating cost
　　Applicability: widely used in relatively soft alluvial strata. The wall thickness is generally 30–150 cm. Not suitable for large blocks of rock, boulders, bedrock, etc. When the standard penetration value is greater than 40, the efficiency is very low.
　　2 Percussion trenching equipment
　　Features: low equipment cost, low efficiency.
　　Applicability: strong adaptability to strata; suitable for general soft soil strata, and can also be used in sandy gravel, cobble, and bedrock.
　　3 Hydraulic trench cutter
　　Features: the most advanced, fast working efficiency, expensive equipment, high cost.
　　Applicability: suitable for different geological conditions, including bedrock. Not suitable for boulder or large isolated rock strata.
　　4 Multi-head drill trenching machine
　　Features: fast excavation speed, high degree of mechanization, but the equipment is bulky and heavy.
　　Applicability: not suitable for cobble or boulder strata, and even less for bedrock.