During the construction process, slope collapse can cause construction difficulties, economic losses and even casualties. There are two reasons for slope collapse, one is the increase of soil shear stress, and the other is the decrease of the shear strength of soil. In order to scientifically develop a construction plan for foundation works, including soil excavation, transportation and filling, it is necessary to study this lecture. In this lecture, we’ll learn construction characteristics of earthwork, step-slope and soil wall support. Earthwork can be divided into site leveling, foundation groove, foundation pit, earth excavation and backfilling; when the excavation depth of foundation pit(groove)exceeds a certain limit, the soil wall should be made into a sloping side slope, and the gradient coefficient an important control indicator; The supporting structures used for deep foundation pit include sheet pile, cast-in-place pile, deep mixing pile, underground diaphragm wall, etc.