Large amounts of granite wastes in the stone processing industry should be recycled to prevent the environmental pollution and health hazards. In this work, the sintered glass-ceramics have been prepared from granite powder by the sintering-crystallization method. The sintering additives were investigated to reveal their influence on the densification, crystallization and flexural strength of glass-ceramics. Compared to colloidal silica and float glass powder, the boehmite sol was more effective in the strengthening of glass-ceramics. The crystallinity of glass-ceramics decreased with increasing the sintering temperature due to the melting of microcline phase, and the microstructure was typical of liquid phase sintering. The crystal phases included anorthite, quartz and hematite. As the boehmite content was increased, the flexural strength firstly increased and then decreased, showing an optimal content of 3 wt%. The maximum flexural strength (125 MPa) was far superior to that of natural granite. The crystallinity continuously increased with the increase in the boehmite content. The sintered glass-ceramics with decorative patterns and high flexural strength promise the practical reutilization of granite wastes in the ornamental tiles.