Abstract: To compare the superiority of nylon jet and teflon jet penetrating without initiating the explosive reactive armor, numerical and experimental study have been carried out. The results showed that it was the dynamic pressure that initiates the sandwich explosive during the penetrating process. The reflection of stress wave between front panel and rear panel aggravates the reaction of sandwich explosive. In addition to the low density, the penetration performance should also be taken into account to choose an appropriate material for liner. Teflon, by contrast, has shown better advantages.