In order to carry out ignition experiment on combustion-driven mixing gasdynamic CO₂ laser based on N₂O/C₇H₈, a liquid N₂O supply system and a N₂O/C₇H₈ mono-injector gas generator were designed. The liquid N₂O supply system, ignition and combustion performances of N₂O/C₇H₈ were studied. Experimental results indicate that N₂O can be supplied in liquid state by the designed liquid N₂O supply system; ignition can be realized under two operating modes(excess oxidizer coefficient is 0.3 or 0.4) in designed time sequence and the combustor pressure is smooth. In addition, with the increase of excess oxidizer coefficient, combustion efficiency improves obviously.