Diaphragm wall trenching is a technology to construct a continuous underground wall for the purpose of the foundation and retaining wall before construction of large scale underground structures. The performacne and capability of rotary multi-horizontal cutter diaphragm wall trencher is expected for future large scale projects such as the construction of underground railway and highway. In developing countries such as China, the demand of this diaphragm wall trencher to be replaced with bucket type trencher which is used only for shallow trenching is enhanced.