Decoupled charge blasting can effectively reduce the peak pressure of the hole wall,thus reducing the range of crushing zone and improving the blasting effect.Air and water are two common coupling media used in practice.Taking granodiorite as an example,the blast loading of these two charge structures is analyzed based on isentropic adiabatic expansion theory and elastic theory.Theoretical calculation results shows that when the charge diameter is 70 mm and the blast hole diameter is 115 mm,the quasi-static pressure load and the peak pressure of hole wall produced by water-coupled charge structure are 5.63 times and 2.15 times of those produced by air-coupled charge structure,respectively,which is beneficial to strengthen the blasting crushing and throwing of rock mass.Moreover,a water-coupled bench cast blasting technology is proposed,which adopts a comprehensive method to optimize the distribution of unit consumption of explosive,blasthole inclination angle and initiation delay.Meanwhile,the process of crushing rock with this technology is illustrated.The engineering application of water-coupled bench cast blasting technology used in the excavation of slope rock mass at Yebatan hydropower station proves that this technology can evidently improve the throwing rate of rock mass to 47.8%,and the average size of rock mass after blasting is 327.3 mm.Additionally,the blasting dust is controlled.The effects mentioned above all help to speed up the construction progress.Application of related technologies can provide reference for similar projects.