Two-dimensional (2D) lattice structures are widely used in lightweight engineering applications due to their tunable mechanical properties [1]. Different lattice topologies, such as square, triangular, and hexagonal, exhibit distinct mechanical behaviors depending on their geometry and loading direction. While individual lattice types offer specific advantages, they also suffer from inherent limitations. A promising strategy to overcome these drawbacks is to stack different lattice topologies into multi-layer (laminated) lattice structures, allowing the combined structure to exploit the strengths of each layer. Previous studies have extensively investigated the effective mechanical properties of single-layer lattice structures using analytical, numerical, and experimental approaches [2]. However, research on the mechanical behavior of multi-layer lattice structures composed of different lattice topologies remains limited. This study investigates the effective mechanical properties of multi-layer lattice structures using analytical and computational methods, with Fig. 1 illustrating a representative multi-layer lattice configuration. The effective properties are first derived analytically based on laminated composite theory [3], accounting for interactions between layers with different lattice topologies. High-fidelity finite element models (Fig. 2(a)) of multi-layer lattice structures are then developed and simulated under various loading conditions to validate the analytical predictions. In addition, homogenized solid-plane models (Fig. 2(b)) employing the derived effective properties are analyzed and compared with the high-fidelity lattice models to evaluate their accuracy and computational efficiency. This comparison highlights the potential of using effective properties to reduce computational costs in large-scale structural simulations. The findings of this study provide critical insights into the design and optimization of multi-layer lattice structures, enabling the development of advanced lightweight materials for applications in aerospace, automotive, and other high-performance engineering fields.