In order to optimize the processing scheme for the brittle zone of shell material,increase the lethality of projectile and enhance the utilization ratio of material,the fracture processes for the alloy steel specimens with no brittle zone,asymmetrical distribution brittle zone and offset-containing crisscross brittle zone were simulated with the display dynamics function of finite element software ANSYS,respectively. Through the change of grid and stress wave as well as the comparative analysis between the drag acceleration and energy conversion in the impact process,it is found that the specimens with brittle zone is more easily broken than those without brittle zone in the impact process. For the specimens with brittle zone,the location for the stress firstly to generate is near the brittle zone,and the fracture occurs along the brittle zone. The comparison between the fracture processes of specimens with both asymmetrical distribution brittle zone and offset-containing brittle zone shows that the energy conversion values are similar to the hammerhead drag acceleration ones. It indicates that the offset of brittle zone has no significant effect on the specimen fracture.