With the development of urban construction, underground space is developed and exploited largely and excavation engineering is widely used. Compared with other support patterns, SMW is more economically potential with many advantages, such as large wall thickness，great depth, good impermeability and environmental protection performance. In this paper, formed steel, antifriction material, characteristic of soil-cement, combination of SMW engineering method and design calculating method are analyzed and summarized. Based on the above, the future of SMW is prospected.