Abstract: In order to study the feasibility of three low-density materials, floatglass, lucite and plexiglas, applied in the forward shaped charge liner of tandem warhead. The formation of three low density jets and the detonation process of explosive reactive armor were numerically simulated by Autodyn-2D. The result shows that low-density jets have higher jet tip velocity, larger jet diameter and better ductility compared with the copper shaped jet under the same condition. The low-density jets initiated the charge of ERA more effectively and rapidly. The feasibility of using three kinds of low density materials as forward shaped charge liner of tandem warhead is verified primitively.