Abstract: The fracture-enhancement technology for deep high-gas coal rock is an important approach for preventing coal and gas outburst disasters. To explore a water-free and efficient coal rock fracturing method, this study proposes a novel technique of high-pressure air-induced sand-driven fracturing. Using a self-developed true triaxial experimental system for high-pressure air impact fracturing, true triaxial tests were conducted under five sand particle sizes (1.00, 0.63, 0.50, 0.25, 0.125 mm) to investigate the fracture morphology of coal rock under sand-laden high-pressure air blasting. Dynamic air pressure curves and acoustic emission monitoring data were analyzed to reveal the influence of sand particle size on the fracture patterns and the spatial distribution of sand particles along the fracture surfaces. The experimental results show that: The number and length of major fractures first increase and then decrease with decreasing sand particle size, reaching a maximum at 0.25 mm, where the fracture network is the most developed; Sand particles are unevenly distributed along the fracture surfaces, primarily influenced by the roughness and undulations of the fracture, and their distribution range increases as particle size decreases, with the widest spread observed at 0.125 mm; Dynamic air pressure and acoustic emission data indicate that at 0.25 mm, the air pressure drops the most and over the shortest time, and the acoustic emission signals exhibit the highest peak and cumulative energy, along with fewer cumulative events. This suggests that larger or more fractures were generated simultaneously under this condition, confirming that 0.25 mm sand yields the most effective fracturing performance and highest energy utilization. The findings demonstrate that high-pressure air-driven sand fracturing improves the energy utilization efficiency of compressed air and significantly enhances the formation of horizontal and vertical fractures compared to pure air coupling, thereby offering an effective means to improve coal rock fracturing performance.