Gahnite-diopside glass-ceramics were prepared with SiO2, Al2O3, ZnO, CaO and MgO as main raw materials, and the mechanical properties of glass-ceramics were improved by self-toughening technology. The influences of heat treatment parameters on the mechanical properties of glass-ceramics were studied by orthogonal test, and the relationships between the proportion of crystal phase, microscopic morphology and mechanical properties of glass-ceramics were discussed. The results show that the fracture toughness of glass-ceramics increases significantly with the increase of diopside phase ratio, but the bending strength of glass-ceramics decreases when diopside phase ratio is too high. Therefore, in order to prepare glass-ceramics with high fracture toughness and bending strength, columnar crystals are required to crisscross and granular crystals are required to fill the gaps, which together play a synergistic strengthening role. When the basic glass with heat treatment at 750 ℃ for 2 h+810 ℃ for 2 h+880 ℃ for 2 h+950 ℃ for 2 h, the fracture toughness of glass-ceramics can up to 5.1 MPa·m1/2, the bending strength can up to 255 MPa, and the vickers hardness is 8.3 GPa.