To study the boulder-blasting characteristics of single-base gun propellant,boulder blasting experiments of the single-base gun propellant and emulsion explosive were carried out,cement mortar blocks with 50 cm in diameter and height were employed to simulate the rock boulders,and powder factor was 0.05~0.25 kg/m3.The variation of fragmentation distribution,crushing energy,and energy efficiency with powder factor of boulder blasting experiments were analyzed.The results showed the boulder-blasting maximum fragmentation size decreased with the increasing powder factor,the energy efficiency barely changed with powder factor.The surface crack distribution and propagation of boulder blasting with single-base gun propellant and emulsion explosive were observed through high-speed photography,which revealed that the rock-breaking mode of single-base gun propellant was significantly different from that of emulsion explosive.The gas pressure raised rapidly with the combustion of single-base gun propellant in the borehole,which lead to the axial and circumferential tensile failure of the boulder.When the boulder was completely broken,the remaining propellant will no longer provide rock-breaking energy.