Research conclusions:Through the analysis of the advantages and disadvantages of the water lowering in and out of the foundation pit in strong permeability soil，the water lowering out of the foundation pit has the following features: (1) The requirement of water lowering can be met for the foundation pit with large water － bursting so that the works above the bottom surface can be done without water．(2) The interference and impact on the construction can be effectively avoided and cut so that it is good for the excavation of the foundation pit and organization and implement of the structure construction．(3) It is good for doing the works of the water lowering and drainage in order．(4) The station construction in later stage proves the prediction of the water － bursting volume of the foundation pit and calculation of the water yield of one well are accurate so that it can provide the reference to the similar works．