In order to study the mechanical properties of platinum needle in grading electrode in converter valve equipment under flow excitation,CREO software was used to establish the flow field 3D model containing platinum needle in grading electrode.The processed model was imported into ANSYS Workbench,Fluent and Transient structural were connected by bidirectional coupling module,then the data transmission interface was defined on the fluidsolid coupling interface.Considering the periodic fluctuation characteristics of flow,the transient analysis of the discrete finite element model was carried out based on bidirectional fluidsolid coupling,then the stress and strain response curves of the platinum needle were obtained.The bending strength of the platinum needle was obtained by mechanical property test.The conclusion is drawn that the maximum stress of the platinum needle in the singleended fixed mode is far less than the bending strength of the material,which meets the engineering requirements.