The explosively formed projectile(EFP) with fins for a cover charge structure by LS-DYNA software which four covers were conglutinated on the liner was studied by three-dimensional numerical simulation. The mechanism of forming EFP with fins was discussed based on the curves of velocity and pressure vs time of the liners. A contrastive analysis was carried out on the three kinds of liners which include big-cone shaped liner, imperfect-sphere shaped liner and arc-cone shaped liner. Results show that three kinds of liners can form obvious fins and the velocity of the big-cone shaped liner is the fastest. The experimental results agree with the simulational results basically.