For the problems of low yield strength, easy deformation, and inability to meet the performance requirements of hafnium plates used in nuclear reactor cores prepared by traditional hot rolling process, hafnium plates with thickness of 5.5 mm were prepared by hot rolling and hot rolling+cold rolling processes. Then, the influence laws of rolling process on the tensile mechanical properties and corrosion properties of hafnium plates were established by observation of metallographic structure and fracture morphology. The results show that when the hafnium plate is prepared by hot rolling + cold rolling process, the slip system is small, and the density of twins and dislocations increases during cold rolling. Compared with the hot rolling process, the grain size of the hafnium plate is smaller, so the strength and yield ratio of the hafnium plate are obviously improved, and its corrosion performance and related physical properties also meet the performance requirements of hafnium plate for nuclear reactor core. Therefore, when hafnium plate is prepared by rolling process, adding cold rolling after hot rolling is beneficial to obtain the hafnium plate with better comprehensive performance.