As a common form of deep foundation pit support, the construction of diaphragm wall is often affected by the engineering geological situation, hydrogeological conditions and other factors. In this regard, this study takes the deep foundation pit project of Guangzhou Science and Technology Library as an example, firstly, on the basis of sorting out the design method, construction technology and related construction process of diaphragm wall, it analyzes the difficulties in the construction process and puts forward corresponding technical measures; secondly, it carries out the research on the main points of the construction technology and the construction technology method and applies them to the construction of diaphragm wall, which achieves good results. This study can effectively reduce the construction difficulty of deep foundation pit diaphragm wall, and has a positive effect on the cost reduction and efficiency of deep foundation pit diaphragm wall construction.