Aiming at the problem of effectiveness evaluation of conventional aerial bomb attacking linear target, the motion process model of the bomb from dropping to explosion is established, and the parameters such as impact angle and slant range are obtained. The error theory is used to deal with the trajectory deviation of the bomb, and the aiming error on the base plane is obtained. The model of the bomb damaging the line target is established, and the equivalent damage length and width of the line target are obtained. Finally, the damage efficiency of a single bomb to the line target is calculated. The calculation results show that the method is reasonable and effective, easy to program, and can calculate the bomb damage effectiveness quickly and accurately.