A kind of one versus one beyond visual range (BVR) air combat model has been established, which includes functional models of radar, missile and fighter and the process of several combat stages. Air combat effectiveness ratio (ACER) is defined to analyse the result. The 2k factor design method is used to design combat test case and analyses the influence of three factors (fighter stealth character, missile range and flight height) on ACER. Simulation result reveals that when RCS of one fighter is reduced from 0dBm2 to -10dBm2 which cannot remarkably affect the opposition fighter’s radar detection distance and missile launch distance, the RCS factor has small influence and the missile range factor has great influence. When RCS of one fighter is reduced from -10dBm2 to -20dBm2, the opposition fighter’s radar detection distance will be reduced and lead the result of its missile launch distance be less than its missile range. Compared with the former case, the effect of RCS factor increases and the effect of missile range factor decreases. However, the effect of height is not significant.