In this paper, the high-strength titanium alloy skeleton structure was prepared by laser selective melting (SLM). Titanium–aluminum composite with different thickness and crystal morphology was formed by smelting the filled aluminum powder/bulk. It was found that diffusion reaction occurred between the interface of Ti–6Al–4V strengthening skeleton and Al–Mg–Sr–Zr alloy matrix, forming a dense metallurgical bonding. The precipitated phases in the interface were mainly TiAl₃, TiAl, TiAl₂ and Ti₃Al₅. With the increase of smelting temperature and holding time, thickness of the interface reaction layer gradually increased, reaching 600 μm at 800 ℃–1 h, which proves strong bonding of the composite structure interface. The elastic modulus of the reinforced skeleton, aluminum alloy matrix and reaction interface was analyzed. It was found that the elastic modulus of the reaction layer (1.2×10¹¹ Pa) was higher than that of the titanium alloy reinforced skeleton (1.07×10¹¹ Pa) and the aluminum alloy matrix (7.1×10¹⁰ Pa). The results provide theoretical basis for the spatial controllable strengthening of aluminum alloys, which is expected to overcome the inverse relationship between strength and toughness of traditional materials.