In order to obtain the flying characteristics of prefabricated fragments of trapezoidal section lethal warhead and provide reference for the design of trapezoidal section lethal warhead, the numerical simulation of prefabricated fragments driven by five kinds of trapezoidal section charge explosion was carried out by ANSYS/LS-DYNA software.The distribution law of fragments,the velocity of fragments on each trapezoid surface and the characteristics of fragments at different initiation points were obtained. The results show that the fragments on the four faces of trapezoid form four fragment bundles. The lower fragment flying angle is the largest, up to 105°.The fragmentation direction on the trapezoidal inclined plane is deflected under the trapezoidal relative to the normal direction of the inclined plane.The maximum deflection angle is 34.5°.When angle θ is smaller than 60°, the average fragment velocity on each surface of trapezoid increases by 8.6%.And the average velocity of fragments on the lower surface of trapezoid is greater than that on the upper surface of trapezoid. A large angle θ will decrease the average velocity of the fragment on the lower surface and the inclined surface of the trapezoid. The maximum velocity fragment is located on the upper part of the trapezoidal inclined plane. The initiation points at different positions on the trapezoidal symmetry axis have little effect on the circumferential scattering angle of fragments on each trapezoidal plane and the deflection angle of fragments on the inclined plane, but can increase the velocity of fragments in the contralateral direction,the fragment on the lower surface increased by 3.6%.The angle θ is 45° and the initiation point is set on the trapezoid, which can make the following fragments obtain the maximum killing power.