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In order to explor the influence of the inclination angle of wedge cut hole on the blasting effect of large-cross section tunnel, Bayueshan Tunnel of Tong’an Expressway was taken as the engineering background. Combined with the rock breaking theory of wedge cutting blasting, the rock mass parameters were obtained with the mechanical experiments, and the wedge cutting models with different inclination angles were established. The influence of wedge cut hole inclination angle on blasting effect was analyzed from three aspects: effective stress, surrounding rock dynamic damage and groove cavity evolution, the best cutting angle of the third grade surrounding rock was put forward. The results show that the effective stress of 60° hole arrangement is the highest, and the damage area of surrounding rock of 70 ° hole arrangement is slightly about 60 °, but the damage area of surrounding rock at the bottom of 60 ° hole arrangement is the most flat. The groove cavity with 60 °holes is the largest, with a maximum size of 2.18 m in horizontal direction and 1.68 m in vertical direction. The average utilization rate of blastholes in the field test is 86.74%, and the unit consumption of explosives is reduced by 0.02 kg/m³. To sum up, the optimal layout angle of cutting holes in grade III surrounding rock is 60°. [ABSTRACT FROM AUTHOR]