Lattice materials are a class of engineered materials with artificially designable microstructures, with excellent multi-physics field manipulation capabilities in mechanics, acoustics, and thermodynamics, and exhibit broad application prospects in the field of smart structures. Although the development of additive manufacturing technology has significantly enhanced the shape complexity of lattice materials, its limitations in build size and manufacturing efficiency still impede the integrated fabrication of large-scale complex structures, which has become a key technical bottleneck for their engineering application. To address this, this paper proposes a prefabricated assembly construction method using standard unit cells, which enables configuration flexibility and manufacturing feasibility for large-scale lattice materials in complex structures via modular construction and spatial assembly. In terms of structural configuration, octahedral lattice unit cells serve as the basic components, with two connection strategies developed: Bolt joints for flexible material systems and bionic plug-in joints for rigid ones, enabling modular assembly for diverse application requirements. For flexible structures, linear actuators are integrated to construct an actively deformable wing structure, which achieves local deformation control with a maximum thickness adjustment range of 25 mm and a maximum surface inclination angle of 12°. For rigid structures, a lattice sandwich cockpit prototype is constructed, and a homogenized finite element model is established for static mechanical analysis, resulting in a bending stiffness of 2564.1 N/mm and a torsional stiffness of 1409 N·m/deg. The research results indicate that this assembled lattice structural system, while maintaining lightweight properties and high performance, possesses good assembly flexibility and cross-scale adaptability, thereby offering an effective configuration and manufacturing solution for the engineering application of smart structures and lightweight aircraft components.