Abstract The finite element software ABAQUS is used to set up the model of large haunched slab.By using the sequential thermal stress coupling calculation method,the validity of the data model is proved by comparing with the experimental results.On the basis of this,the fire resistance of large haunched slabe is analyzed.The fire resistance limit of large haunched slabe with different thickness of protective layer is obtained,which provides reference for the fire resistance design of large haunched slab.