In order to study forming laws of circumferential MEFP, circumferential MEFP structure, the circumferential MEFP simulation model by AUTODYN software and stimulated from the liner parameters and warhead structure parameters. The results show that adjustment of liner diameter and curvature radius has little effect on EFP forming speed, but incensement of the liner thickness will slow the EFP forming rate significantly; the curvature radius and thickness of the liner affect the lengthdiameter ratio of EFP obviously. Circumferential MEFP warhead shell thickening and usinghigh explosive will make the EFP forming speed and the ratio of diameter increase.