The dislocation etch pit density (EPD) of the 2-inch diameter n-type (100) Te-GaSb single crystal grown in batches by the liquid encapsulated Czochralski (LEC) method is usually lower than 300 cm-2, reaching dislocation-free level. In this paper, the lattice perfection and subsurface damage of this GaSb single crystal polished substrate were characterized by X-ray rocking curve and reciprocal space map (RSM). The results show that after chemical mechanical polishing with optimized process conditions, the surface of GaSb single crystal substrate is atomically smooth, and there is no subsurface damaged layer. High-quality type-Ⅱ superlattice epitaxial materials can be stably grown on this substrate by molecular beam epitaxy and exhibit excellent infrared detection performance. On this basis, the internal relationship between the physical properties, growth preparation and substrate processing conditions of GaSb substrate materials was comprehensively analyzed.