Abstract: In order to solve the radar resources scheduling problem in the case of multiple directions and complicating ballistic missile fire attacks, the ballistic missile fire attack scene is analyzed in details. The mathematic model for the early warning and detection network is established based on target state assessment. Detection period division and radar target pairing in each period, a solution to the model is obtained by using software algorithms．Finally，a simulation example is given to verify the validity of the model and the correctness of the algorithm．