Near-Earth asteroid impacts have the potential to cause catastrophic damage, making it imperative to develop robust defense strategies to mitigate these risks. Understanding Near-Earth asteroid impact dynamics and potential effects becomes crucial for global disaster preparedness and response efforts. This study presents an impact index model designed to guide preliminary defense strategies against near-earth asteroid impacts, which pose significant threats to humanity. The model is informed by numerical simulations and engineering calculations, providing a high-fidelity analysis suitable for fine-grained assessment of impact effects. This paper adopts principal component analysis and factor analysis to optimize the impact index model, catering to asteroids with incomplete observational data. The research investigates the effects of asteroid disintegration, explosion, and tsunami, enhancing the formulation of defense policies and deepening the understanding of impact effects. The study’s results indicate that the proposed model can effectively assist in preemptive strategic planning to mitigate potential disaster losses.