With the development of infrared guided weapons, the survival of combat aircraft is facing a huge threat. Numerical simulation and experimental research were conducted to investigate the effect of different cooling efficiency of liquid cooled plug cones on the infrared radiation characteristics of aeroengines equipped with two-dimensional plug nozzle. The research results indicate that cooling the plug cone can effectively reduce tail direction Infrared radiation characteristics of the aeroengine in 3 ~5 μm waveband. For the infrared radiation of the aeroengine jet, liquid cooled plug cones can effectively reduce the infrared radiation of the jet. When the cooling water flow is 0.1 kg/s, 0.2 kg/s and 0.3 kg/s, the mean value of jet infrared radiation characteristics at 0 ° ~90 ° can be reduced by 31.9%, 53.5% and 68.7% in 3 ~5 μm waveband. For the wall surface radiation of the aeroengine, when the cooling efficiency of the plug cone is in the range of 0.3 ~ 0.7, the wall surface infrared radiation characteristics of the aeroengine at the tail direction 0° ~ 30° decrease rapidly with the increase of cooling efficiency. When the cooling efficiency reaches above 0.7, the decreasing trend of wall surface infrared radiation characteristics at the tail direction 0° ~ 30° of the aeroengine slows down. The experimental results show that when the cooling water flow is 0.3 kg/s, the cooling efficiency of the plug cone reaches 0.876. The mean value of the aeroengine infrared radiation at 0° ~ 10° can be reduced by 94.77%.