Abstract: The FDM (finite difference method) model of temperature field and thermal crown of work roll on 1700 hot strip mill (HSM) was studied. The off-line simulation program was compiled by C++ language and the temperature field and thermal crown were calculated according to the rolling schedule, thus obtaining roll surface temperature and thermal deformation at different moments. The maximum surface temperatures of the work rolls F2, F3 and F4 are about 58.1, 73.1 and 81.2°C and relevant maximum radial deformations are about 193.979, 275.259 and 333.433 μm respectively. The surface temperature distribution and thermal deformation were both affected obviously by roll shift. The computed and measured roll surface temperature were comparatively in good agreement with each other, and the fact showed that the computed roll temperature field and thermal crown model are quite accurate.