<p>Pressurized oxy-fuel combustion is a potential combustion technology with high efficiency and low-cost CO₂ capture capacity. However, there is currently limited research on the basic experimental due to the difficulty of experiments, with the predominant focus residing in low-pressure regimes and a dearth of exploration in high-pressure environments. Since the ignition and devolatilization is as the initial step, contributes significantly to the process of coal combustion, this study examines the ignition and devolatilization characteristics of single bituminous coal and anthracite particles in O₂/CO₂ condition under pressures of 0.1 to 4 MPa using a visualized high-pressure drop tube furnace (HP-DTF). The dynamic combustion process at this high-pressure environment is captured, facilitating the determination of ignition delay time (IDT) and devolatilization time (DT) of single-particle coal. The results demonstrate that the IDT of coal particles will be lengthened relative to the ambient pressure under the fixed oxygen volume fraction. Bituminous coal and anthracite exhibit homogeneous ignition and heterogeneous ignition respectively. Bituminous coal initially experiences a rapid increase in IDT, followed by a gradual decrease; the drastic change of gas phase properties and the release of volatiles are the main factors leading to the increase of ignition delay, comparing to with 0.1 MPa pressured oxy-fuel combustion. The promotion of volatile ignition occurs as a result of increased oxygen partial pressure and a higher heat transfer coefficient, which leads to the shortening of the subsequent IDT. Also, the devolatilization time of bituminous coal showed a positive correlation with pressure, and the value at 4 MPa is about twice that at atmospheric pressure. In summary, this study of the coal ignition deepens the understanding of flame characteristics in the pressure oxygen combustion, which lays a solid foundation for the future pressured oxy-fuel combustion industrial application.</p>