Abstract: The formation process of explosively formed penetrators (EFPs) with fins formed by three-point initiation was simulated by using LS-DYNA software. The structure and intensity of detonation waves in the transmitting process as well as the distortion characters of the liner formed by the composite detonation waves were theoretically studied to deeply understand the formation mechanism of EFPs with fins. The threepoint initiation device was designed and the EFP charges were tested. The results show that the designed three-point initiation device is reliable and can meet design requirements of EFP charges, and the shapes of the EFPs obtained in the experiments are stable which are in agreement with the simulations. And the speed drops of the EFPs with fins in the fly processes decrease and the stabilities increase.