The structure of a reverse flow combustor is more complicated than that of a straight flow combustor. To study the flow and combustion characteristics of the reverse flow combustor， planar particle image velocimetry （PIV） is used to measure the cold flow field， and the flame structure and propagation process are obtained by means of spontaneous chemiluminescence signals. It is found that the flow field of the reverse flow combustor is not symmetrical， and the velocity distributions near the inner and outer walls are different. In addition， the total change has little effect on the flow field structure of the combustor， but the velocity magnitude increases with the increase of the total pressure loss. Most combustion takes place in the primary combustion zone and the middle zone， and the flame burns out in a certain crescent shape. The ignition process of combustor has been divided into four stages， including the flame nucleation generation stage， the flame nucleation development stage， the successful ignition stage and the flame stabilization stage. It is shown that the ignition of the toroidal recirculation zone is the key to a successful ignition. During the blowout process， the flame core approaches the back of the toroidal recirculation zone， and the root of flame gradually moves away from the exit of the swirler， and the flame evolves from the crescent-shaped structure during the normal combustion to a single flame.