Abstract: Grillage flexible supporting structure with prestressed anchors has been widely used in foundation excavation engineering because of its many advantages. The present design mainly focuses on the strength design, and there is little study about the horizontal displacement of supporting structure. But with the increase of excavation depth and scale, the displacement and stability problem is becoming a focus in engineering world. Considering the influence of excavation process, based on an engineering example, the influencing factors of the horizontal displacement of wall facing of grillage flexible supporting structure with prestressed anchors are analyzed. These factors include excavation depth, slope angle, construction load above ground, physico-mechanical properties of soil, supper-excavation depth, design parameters of anchors as well as the bending stiffness of grillage vertical columns. Through analysis, some qualitative conclusions are drawn for the influences of partial factors, and some quantitative results are given for the influences of the rest factors. In general, the above conclusions provide some reasons for further understanding the work mechanism of grillage flexible supporting structure with prestressed anchors and are useful references for engineers.