In order to assess an incendiary bomb damage capability, the pierced and ignited combustion probability on tankers and ammunition boxes was calculated by programming, and the influence efficiency evaluation factors were analyzed: the number of the ammunitions, the spread variance, and the dispersion radius of ignited and cast torch. The results show the major factor of damage efficiency is the spread variance and the dispersion radius of the ignited and cast torch is better designed as 40~60m under the specific target area and distribution.