The combustion chamber is a critical component of an aeroengine, significantly influencing its performance and reliability. The characteristics of the internal flow field are fundamental to both the design and optimization of the combustion chamber. To investigate the flow field distribution characteristics of a double-head reflux combustor, this study both experimental and numerical simulation methods was utilized. The flow field characteristics inside the flame cylinder under hot conditions and the impact of varying inlet/outlet pressure differences on the internal flow field was focused. The results show that at inlet/outlet pressure differences of 1 500 Pa, 3 500 Pa, and 5 000 Pa, the flow field distribution characteristics inside the double-head reflux combustion chamber are similar. Additionally, the velocity within the combustion chamber increases as the inlet/outlet pressure difference increases. Under identical cross-sectional conditions, the flow field distribution characteristics in the simulation closely match those observed experimentally. The aforementioned research findings provide valuable technical support for the optimization design of the combustion chamber's flame tube.