Abstract: Current research on explosive sintering of Ni-Al energetic structural materials is mostly restricted to small-diameter specimens of Φ18 mm and below. To fabricate large-size Ni-Al energetic structural materials with both high relative density and superior reaction reactivity, and to validate the feasibility of specimen scaling-up, nickel powder with an average particle size of 19.8 μm and aluminum powder with an average particle size of 24.7 μm were blended at a molar ratio Ni:Al = 1:1. The explosive sintering process of Φ18 mm samples was simulated via the AUTODYN finite element code, and process parameters were optimized with theoretical calculations. Large-size Φ50 mm Ni-Al energetic structural materials were subsequently manufactured by explosive sintering.Density measurement, scanning electron microscopy (SEM) and X-ray diffraction (XRD) were adopted to characterize the relative density, microstructure and phase composition of the specimens, respectively. Quasi-static compression tests were carried out to evaluate the mechanical properties of heat-treated materials. The experimental results reveal that the as-fabricated Φ50 mm samples possess an average relative density of 99.1%, and their microstructures show no obvious distinction from those of Φ18 mm specimens. Only diffraction peaks of elemental Ni and Al are identified after sintering without the formation of Ni-Al intermetallic compounds, which facilitates the retention of subsequent chemical reactivity of the material. The Al phase presents a continuous distribution, with Ni particles homogeneously dispersed inside, leading to uniform dual-phase distribution. After heat treatment, the Φ50 mm specimens achieve an average compressive strength of 281.5 MPa and an average failure strain of 17.8%, whose mechanical properties are roughly equivalent to those of Φ18 mm counterparts. It is concluded that large-size fabrication of Ni-Al energetic structural materials via explosive sintering can be realized by optimizing process parameters on the basis of numerical simulation and theoretical calculation.