The traditional shaped charge is often used to detonate the projectile charge when dealing with abandoned ammunitions. This disposal method cannot meet the requirements of resource conservation and environmental protection. Based on the “penetration without detonation” damage characteristics of low-density jet to shelled charge, a linear shaped charge simulation model was established by using PTFE and its composite materials as liner materials. The process of cutting 122 mm abandoned ammunition by jet formed under different initiation modes was simulated. The results show that the pressure and propagation velocity of one-dimensional plane detonation wave formed by surface initiation charge are greater than those of divergent detonation wave formed by point initiation charge. The PTFE jet formed by the two initiation methods can not completely cut the abandoned ammunition. The PTFE/Cu jet formed by the surface initiation could completely cut the abandoned ammunition and don’t detonate the internal charge. Subsequently, the explosive is poured out and reused by high-temperature melting to achieve the purpose of saving resources. This study will provide a green approach for the disposal of abandoned ammunition.