In this paper, a composite realization method is designed which using a three-axis flight motion table simulates the bomb's attitude and the movement of line of sight in the multi-mode combined guidance system. Firstly, the technical principle of the synthetic line of sight method and coordinate system is summarized, the angular velocity vector conversion and its mapping relationship between software and hardware space is given. The realization process of the synthetic target line of sight semi-physical simulation is investigated, and the methods of solving the drive data of the three-axis simulation rotary table and injecting angular velocity into the line of sight of the guide head stabilizing loop are deduced. Finally, the mathematical simulation of the synthetic target line of sight method is carried out. The optical axis motion law of the guide head tracking the target as well as the target deviation angle and the command output of the bullet eye line-of-sight angular velocity are consistent compared with the real line-of-sight simulation method, which providing a new emulation means for the support application of the bullet eye line-of-sight motion in the semi-physical simulation of the multi-mode composite guidance, as well as the simulation application of the method to provide technical support.