Abstract: In order to study the supporting structure of deep foundation pit under the condition of deep soft soil layer in Zhuhai area，combined with the case of foundation pit，the key and difficult points of foundation pit support are analyzed，and the design points of foundation pit support are clarified. Based on the comparative analysis of the key points of supporting structure design，plane layout，technical economy and construction period，the supporting structure of deep soft soil foundation pit is finally determined. The case foundation pit adopts the supporting structure of pile top slope + cast-in-place pile + internal support + pre⁃ stressed anchor cable to meet the design and specification requirements. It is an effective idea for the design of foundation pit support in deep soft soil layer to compare and analyze the control indexes，clarify the key points of support design，and then determine the support structure of foundation pit.

Key words: deep soft soil foundation pit, supporting structure, control index