The invention relates to a method of a radar for recognizing true and false warheads. The method comprises the steps that a, a state vector capable of reflecting the characteristic of a target warhead is constructed; b, the motion difference of the target warhead is mapped to a state matrix; c, the relation of an observed quantity and the motion state vector of the target warhead is built; d, hypothesis testing is built; e, the sudden change of the motion model of the target warhead is detected by utilizing a detection theory in signal processing to recognize whether the warhead is true or false. The method of the radar for recognizing the true and false warheads can fast detect the motion characteristic change of the target warhead of the radar and accurately recognize the true and false warhead targets.