Based on observation data and ballistic trajectory theory, a simple model is established to analyze the influence of atmospheric vertical structure on the weather modification rocket ballistic trajectory during the ascending phase of rockets. The results indicate that the strength and direction of the horizontal wind field have significant impact on ballistic trajectory, especially in low-level wind fields below 1000 m height. The impact of air density is relatively small. The model could be beneficial for ballistic correction, includ-ing ballistic height, deflection, and distance, and would provide relatively accurate prediction trajectory for weather modification rocket.