A kind of explosive stemming apparatus with detonating cord was placed in a simulated blast hole to evaluate its blocking effect,and then a uniaxial compression test was performed on it using a universal testing machine.The result showed that the compressive strength of the explosive stemming apparatus after being in contact with the blast hole wall was 26.5~35 MPa,and the shear strength was 3.07~3.4 MPa,which was much higher than the shear strength of conventional stemming materials(0.09 MPa).The explosive stemming apparatus was applied on cut blast in tunnel excavation together with optimizing the original blast hole layout.It turned out that the number of cut holes reduced by 35% compared to before optimization while maintaining the same excavation depth,and the hole spacing increased accordingly,which reduced the risk of piercing adjacent cut holes and effectively improved construction efficiency.Therefore,combining the explosive stemming apparatus with stemming material can greatly enhance the blocking effect and prevent premature gas escape.This effect can further extend the gas action duration in the blast hole,and improve the throwing effect of explosion gases by fully exerting the gas wedge rock breaking effect.