In this paper, general characteristic of soft foundation pit is firstly introduced. The deformation and instability which often occur in soft foundation pit is analyzed and some conclusions are found, i.e., to control the deformation of these pits is the key point. Therefore, the application of composite soil-nail in soft foundation pit is suggested and some specific problems are discussed. Also, some good engineering cases are listed here to prove the effect of this approach. The case applications show that composite soil-nail is effective indeed for soft foundation pits if key steps are well controlled during the process of construction.