Intense neutron irradiation can cause severe displacement damage to metal components, causing key problems such as thermal/mechanical degradation [1]. Accurately understanding, predicting and regulating the irradiation damage behavior is key to improve the anti-irradiation ability of materials. Therefore, a sequential multiscale simulation platform was established for modeling displacement damage in metal, by developing the accelerated cascade-annealing model (IM3D) [2], the short-term defect dynamic evolution model (MMonCa) [3] and the long-term defect dynamic evolution model with time-space-correlation (IRadMat) [4]. The evolution of displacement defects in Fe/W-based metals under neutron irradiation and its effect on the macroscopic properties of materials were studied, which are consistent with experiments. It shows that: 1) The intra-cascade time-space correlation effect greatly affects the long-term evolution and size distribution of defects, which dominates the displacement damage behavior in materials. 2) Neutron pre-irradiation damage as new sinks of H/He aggravates the H/He retention and surface damage near the surface [5]. This provides theoretical guidance for the selection/design of new radiation resistant metals and the analysis/prediction of their displacement damage effects.