Using airborne weapons to attack moving targets is a practical research problem. The problem of accurate bombing of moving targets with incomplete information is solved by using mathematical method in pre-calibration. It is of great value in engineering application. However, the present method has many disadvantages, such as too many process links and the difficulty of both pre-calibration and aiming. An improved pre-calibration bombing trargeting method is proposed. The controllable calibration symbol is used to replace the calibration symbol based on continuously computed impact point principle, which improves the regularity of calibration sign change, reduces the difficulty of calibration and aiming, and gives the calculation model of the target synthetic velocity under the proposed method. Combined with ballistic calculation and the target motion hypothesis, the calculation equation of aiming signs is established. Finally, the simulation analysis of typical moving targets is carried out, and the law of error variation of the proposed method is discussed.