Abstract: In order to study the similarity of mechanical properties between a scale model and a full-scale model due to high temperature, and to obtain the fire resistance of the full-scale model through the results of the scale model, the full-scale model of 12 reinforced concrete columns is designed, and the corresponding 2/3, 1/2 and 1/3 scale models are established based on the similarity theory. The actual heating curve, axial force and displacement loading rate of each scale model are adjusted according to the scale ratio. The fire resistance of each model was analyzed based on ABAQUS, and the high-temperature mechanical properties of the scale model and the full-scale model were compared. The results show that: by adjusting the structural similarity, time similarity and temperature field similarity, the section temperature distribution, the axial displacement at the top end of a column, the fire resistance and ultimate bearing capacity of the scale model and of the full-scale model have good similarity, and the fire resistance of the full-scale model of a column can be relatively accurately obtained through the scale model of the column.