Aiming at the multi-arms force demand analysis of system confrontation for naval point area air defense, the Lanchester equation was used to describe the multi-arms confrontation process. The concept of “soft” fire unit was introduced. And the defending target was equivalent to one kind of “arms” with appropriate kill factor. Then, a troop force multiplication ratio was introduced to correct the effect of electronic countermeasure on the total force battle index. Finally, the demand for troops was solved based on multi-stage normative operation theory. And the giving example shows that the proposed method can provide decision-making support for the planning of naval point area air defense forces in system confrontation.