This paper introduces an engineering of foundation pit support in Zhengzhou. Because of the complex surrounding environment and soft soil in the depth range of foundation pit, the combined application of slope protection pile, pre-stressed anchor cable, perforated pipe pile and passive soil consolidation around pile were used to ensure the safety and stability of 17~20m deep foundation pit wall and the existing buildings. Especially with once-forming anchor construction technology by high pressure, the hole-forming difficulties in silt and soft soil below water table were solved and the anchor cable quality was improved.