Abstract: Many factors of influence exist when a jet reacts on explosive reactive armor.The whole process of reactive armor disturbing a jet is discussed adopting numerical simulation.A three-dimensional finite element model of reactive armor and shaped charge is built up and simulation is carried out using ALE method.The figures of reactive armor disturbing jet at different time and the velocity grade curves of jet in front and back of disturbance are received.Computer simulation results showed that the effect of reactive armor disturbing jet becomes greater while the angle of reactive armor increase.The simulation results are in good agreement with experimental results.