To study the local buckling behaviour and failure mechanism of stainless steel components in fire， axial compression tests of eight austenitic welded I-section stub columns were introduced， which included six elevated temperature tests and two room temperature reference tests. In addition， this study analyzed their instability mode and local buckling bearing capacity， meanwhile， the important influence factors on column local stability were analyzed using numerical parametric studies. The current European design method was evaluated on the basis of the experimental and numerical data. The results show that as the temperature increases， the stiffness of the specimen decreases， the buckling deformation increases and the local buckling resistance decreases； the initial imperfection has little effect on the resistance of the specimen， and the section width-thickness ratio is the key factor affecting the local buckling resistance； the predictions of the current Eurocode design method are relatively accurate.