At present, electromagnetic protection is not considered in the general standard of armored vehicle performance evaluation, it cannot adapt to the rapid development of weapons and equipment. In order to study the quantitative influence of electromagnetic interference and electromagnetic damage on the effectiveness of armored weapon system, and verify the necessity of considering electromagnetic factors, this paper takes armored vehicle weapon as an example to evaluate the effectiveness. The armored vehicles in the general performance analysis method, simulation of interference caused by performance degradation by modeling the effects of electromagnetic interference on the attack ability and communication ability to command, and for numerical simulation of interference effects. The simulation results show that even if tiny electromagnetic interference and electromagnetic damage can also cause serious impact on the operational effectiveness of weapon equipment performance evaluation, so it is necessary to consider the problem of electromagnetic protection, electromagnetic protection as an important factor into the evaluation index system.