In order to improve the accuracy of ballistic missile midcourse recognition, an event decision-making method based on Case-Based Reasoning (CBR) is proposed.First of all,according to the actual situation, the requirements of ballistic missile midcourse recognition is analyzed reasonably, and the frame representation method is used to categorize the ballistic missile attack scenario according to their different attributes, and the different attributes are weighted according to specific cases.After that,the similarity of different attributes is calculated to match the most suitable plan.The tested plan can be directly used to guide the actual combat after simple adjustment.Finally,an example is given to verify the proposed method, which has proved its feasibility.