Fighter aircraft stealth performance can decrease effective detection range and the pre-warning time of the defender’s air defense early warning system. Stealth performance of Red Army fighter aircrafts and Blue Army fighter aircrafts are analyzed. Their mutual detection range is estimated. And the influence of detection range on the threat level is simulated by using Matlab. When stealth fighter aircraft and non-stealth fighter aircraft coexist, multi-aircraft cooperation detection mode is researched and four fighter aircrafts passive cooperation location by the stealth fighter aircraft and non-stealth fighter aircraft is realized. Results indicate that the detection range and the threat level to the radiation source is increased, making non-stealth fighter aircraft capable of confronting stealth fighter aircraft, and realize locating and attacking opponents earlier over a long distance.