Utilizing a laser-heated aerodynamic levitation melting technique, we prepared a series of aluminosilicate glasses (xAl2O3·(100-x)SiO2, 30≤x≤63, in molar fraction). The Vickers hardness (HV) and crack resistance (CR) of the glasses were investigated by a micro-hardness Vicker tester. The results show that the hardness of those glasses increases gradually with the increase of Al2O3 content, and the maximum hardness is 8.94 GPa as x=63. However, the crack resistance of the glasses is nonlinear with the change of composition, and the maximum crack resistance is 19.49 N as x=63. According to the results of structural analysis, the increase of atomic packing density and mean-field bond energy density can be attributed to the hardness enhancement. The reduction of the phase interface can lead to the reduction of the crack resistance, while the increase of Al2O3 content in the glass can result in an increase in the crack resistance. The synergy and competition between the phase interface reduction and Al2O3 content increase can result in a nonlinear change of crack resistance. The crack resistance does not change significantly due to the similar structures of the glasses within the mullite phase region.