Abstract: This study investigates the propagation law of a precursor pressure wave and the intensity change of the pressure wave using a high-speed shading system and an overpressure detection system to determine the influence of different dosages on the deflagration effect of a high-energy combustion agent. The high-energy combustion agent used in this experiment assumed potassium perchlorate as the main oxidant, with its mass concentration controlled between 60% and 75%. Amine oxalate was used as a reducing agent, with a mass content of 20% to 30% to balance the oxidation reaction and promote full release of energy. In addition, to improve the combustion characteristics, 0–10% by mass salicylic acid was added as an auxiliary reducing agent, which positively impacted the overall combustion effect by regulating the combustion rate or improving the properties of the combustion products. Three drug packets of the same size were designed with the dosage as a variable, and four pressure sensors were placed in different locations to comprehensively measure the pressure wave. One polyvinylidene fluoride piezoelectric thin film pressure sensor (PVDF pressure sensor) with a sampling frequency of 0–30 MHz and a range of GPa, two CY-YD-202 overvoltage sensors with sampling frequencies of 200 kHz and 0–15 MPa, and one CY-YD-202 overvoltage sensor with a sampling frequency > 100 kHz and 0–10 MPa were placed at measuring points 1, 2, 3, and 4, respectively. By analyzing the shadow photos of the precursor pressure wave and combustion gas fluctuation, comparing three types of dosage pressure wave propagation process, speed change, and pressure change, and combining the theoretical analysis and experimental results, we obtained the precursor pressure wave in the air flow field, pressure velocity evolution, and pressure distribution, as well as the feasibility of the high-energy explosive combustion agent rock theory. These results indicate that the high-energy combustion agent entered a long combustion process following ignition. The combustion agent released a large amount of high-temperature and high-pressure gas, which accumulated temperature, increased the pressure inside the package, and eventually reached the pressure. Upon reaching the cracking pressure limit of the package, the precursor pressure wave and combustion gas propagated outward irregularly from the center of the combustion source, and then the two gradually separated. The precursor pressure wave travels faster, while the pressure wave travels further away simultaneously. The higher the dosage, the shorter the tire pressure process, the faster the propagation speed of the precursor pressure wave, the higher the high-temperature and high-pressure gases produced by combustion, the better the crushing effect of the drug package, and the more regular the propagation of the precursor pressure wave and combustion gas. The overpressure peak pressure, pressure wave positive pressure time, and peak impulse showed an increasing trend with increasing drug dosage. The deflagration effect of the nonexplosive high-energy combustion agent, propagation form of the precursor pressure wave, and rock-breaking ability are directly proportional to the dosage of the drug; the higher the drug dosage, the more powerful the high-energy combustion agent.