<p>The detonation of the commercial explosive in drilling blasting is non-ideal detonation. The detonation performance is related not only to the physical and chemical properties of the commercial explosive itself, but also to the blasting conditions. In this study, the non-ideal detonation model for explosive was developed by adopting the three-term ignition and growth reaction rate equations for the chemical reaction rate and the Jones–Wilkins–Lee (JWL) equations of state (EOS) for its detonation properties. This model was used to investigate the non-ideal detonation characteristics and explosive-rock interface of commercial explosives. The accuracy of the non-ideal detonation model was verified by comparing the numerical and experimental results of explosive with different charge diameters. Furthermore, the effects of explosive densities, rock types, and charge diameters on the detonation performance and rock fragmentation effect were discussed based on experiments and numerical simulations. As a result of the non-ideal behavior, these commercial explosives usually react below their ideal detonation velocity. The results show that the detonation velocity of explosive with different densities is different, the increase of charge density improves the detonation velocity of explosive in the hole, resulting in an increase in the detonation pressure acting on the hole wall, thereby reducing the maximum size of the broken rock and improving the rock fragmentation effect. With the increase of p-wave velocity and rock mass strength, the blasthole is more constrained by rock, and the detonation velocity of explosive increases, but the rock mass strength becomes the main factor affecting the fragmentation effect. As the diameter of the charge increases, the detonation velocity of the explosive increases, the damage range of the rock around the hole becomes significantly larger.</p>