In response to the low altitude breakthrough problem of ballistic missiles facing early warning radar detection, this study measures the breakthrough effect based on the time of ballistic missiles being captured by early warning radar and conducts research. By analyzing the characteristic parameters that affect breakthrough, the influencing factors of the capture time of ballistic missile breakthrough and the entire process of low altitude breakthrough were clarified. A calculation model for offensive and defensive confrontation was developed based on the velocity, threat angle, and radar cross section (RCS) value of the ballistic missile. Simulation analysis of the impact of capture time on ballistic missile penetration. The result shows that when facing warning radar, the capture time of different ballistic missiles increases with the increase of RCS of the incoming missile, and decreases with the increase of velocity.