In this paper, combined with the latest development in relevant diagnostic and modeling techniques, the intense-pulsed ion beam (IPIB) energy deposition model in solid targets is established. The power density distribution induced by IPIB is simulated by Monte Carlo method on the basis of energy balance. By taking the power density as the source term, the thermal field distribution and evolution on a 100 μm stainless steel target irradiated by IPIB are simulated using the finite element method (FEM) in a time scale of several ms. Results reveal that in a time scale of several μups after IPIB irradiation, the main feature in the induced thermal field is a thermal shock within the depth of several times of the ion range. In the time scale of ms, thermal equilibrium can be established between the front and rear surfaces of the target, and the cross-sectional temperature field profile has a similar profile to the cross-sectional energy density distribution of the ion beam. This proves that by the infrared imaging diagnostic method, high resolution cross-sectional energy density diagnostics of IPIB can be achieved with a shooting time delay in ms scale.