When detecting the integrity of pile foundation,we usually take the low strain dynamic test.But for the high pile wharf in service,we need to cut pile for setting excitation and sensor.Using the finite element software ANSYS,and taking single straight pile as the research object,we study the pile body stress caused by injury of pile based on the comparison of intact pile and injured pile.Calculation results show that the cutting pile has little impact on the displacement of pile.But it leads to the stress concentration,while the most unfavorable section transforms from pile bottom to the cut areas,causing potential safety hazard.The influence of the stress concentration caused by different horizontal forces and the influence of the preloading stress on the bearing capacity of pile foundation are analyzed.The scope of influence is presented and relevant suggestions are put forward.