Abstract: In the light of geological conditions of Nanchang Greenland Center Plaza, staged implementation of partitioned neighboring excavations and impact on the surrounding environment, some key technologies are described, such as the constant thickness steel cement-soil wall constructed by TRD (trench cutting re-mixing deep wall) method. The general scheme for D area, that is, the 'center island' method and the combination of various support systems is introduced. The design method for excavation engineering with the combination of various supporting systems under complex environment is discussed.