To compute the operating range of the advanced infrared detector for the stealth aircraft, the combat simulation scenario of F-22 and F-35 is given in the paper. In the scenario, the infrared radiation intensity of F-22 is computed in middle wave-band and long wave-band, the fitting formula of the atmospheric transmittance is given under typical conditions, the characteristic parameters of the F-35 airborne IRST and AIM-9X infrared seeker are inferred and the operating ranges of F-35 airborne IRST and AIM-9X infrared seeker for F-22 are computed with the gradually approaching method. The computation shows that F-22 has good stealth capability and the operating ranges of F-35 airborne IRST is less than 62 km from the nose of F-22 while the infrared dog-fight missiles threat F-22 in short range strikes. The infrared radiation of F-22 is sensitive to the detection angle of the infrared sensors, thus in the aircraft fleet anti-stealth infrared detection, sparse formation is adopted to increase the detection probability.