The application of shaped charge blasting in smooth blasting during chamber excavation is investigated. Based on the principle of shaped charge jets, an arc-shaped charge structure is proposed. Numerical modeling of arc-shaped charge blasting (ASCB) is established and compared with cone-shaped charge blasting (CSCB). The findings indicate that ASCB consumes 43.4% less explosive than CSCB, and the efficiency of ASCB in the charge direction surpasses that of CSCB by 25.97%. Upon reaching the blast-hole wall, the shock wave of ASCB is more concentrated than that of CSCB, facilitating the formation of initial cracks in the energy-gathering direction. The pressure exerted by ASCB on the energy-gathering side of the blast-hole wall is 6.26% higher than that of CSCB, whereas the pressure on the non-energy-gathering side is 37.34% lower. The crack length generated by ASCB in the energy-accumulation direction is approximately twice that of CSCB. Consequently, it is concluded that the shaped charge blasting effect of ASCB is superior to that of CSCB. These research outcomes offer a novel approach for directional presplitting blasting.