Abstract: Taking a fighter aircraft as the research object, the flow field calculation model of the aircraft was established by the three-dimensional modeling and meshing process, and the numerical simulation of the flow field characteristics of the aircraft was carried out based on the commercial CFD software ANSYS Fluent 16. The effect of solar radiation on the temperature field of the fuselage was considered by using the solar ray tracing algorithm, the discrete ordinates method for DO radiation model was used to calculate the iterative calculation of the radiation transfer equation, simulating the after-combusting tail flame injection process with component transport model without chemical reaction (Species Transport Model), and the temperature, concentration and component distribution data of the outflow field of the aircraft were obtained. The influence of solar radiation on the whole temperature field distribution, the influence of the Mach number on the infrared radiation of the flow field and the distribution of tail flame flow field were simulated and analyzed. Analysis shows that the effect of solar radiation on heating of the skin is only about 5 K. With the increase of the number of Mach aircraft fuselage and the difference of infrared radiation intensity is highest in the abdomen, abdominal radiation intensity is about 2 times the maximum radiation intensity. Under the shock wave, there will be the core high temperature region with the highest two 450 K and 580 K discontinuity at the rear of the tail flame. The infrared radiation intensity distribution of the plume conforms to the pear shape distribution trend.