To explore the influence of ordinary hexogen (RDX) and high density spherical RDX on the properties of cast explosives, the crystal morphology, thermal stability and mechanical sensitivity of the two kinds of explosives were evaluated by scanning electron microscopy(SEM), differential scanning calorimeter(DSC) and etc. Taking typical casting formulation as an example, the influence of RDX type on slurry viscosity, density of cylinders, detonation velocity and shockwave sensitivity was discussed. Results show that high density spherical RDX has smooth surface, few crystal defects and high sphericity. The apparent activation energy and enthalpy of activation of high density spherical RDX is 10.79 kJ·mol^-1 and 10.81 kJ·mol^-1 higher than that of ordinary RDX. The impact and friction sensitivity of high density spherical RDX is 20% and 8% lower than that of ordinary RDX. Comparing with ordinary RDX, the high density spherical RDX-based cast formulation shows 41%-45% and 10%-14% decrease in the slurry viscosity and shockwave sensitivity, together with 0.6%-3.9% and 1%-3% increase in the density of cylinders and detonation velocity, respectively showing a better process properties, detonation properties and safety properties.