Abstract: The distortion of a liner under sliding detonation is studied. Making use of the momentum conservation law, the spin velocity of an explosively formed projectile is obtained. Impulse acting on the liner fluted surface is calculated by slippage detonation. And the distortion of liner with different angle, thickness and different fluted angle, fluted depth is simulated. The results showed that impulse acting on the liner fluted surface is the main complication producing rotation of EFP and the rotation velocity of EFP is related to the liner angle, liner thickness, fluted angle and fluted depth.