Considering the suppression of transmitting deceptive jamming in radar countermeasure, a discrimination method based on frequency diversity array was proposed. In FDA(frequency diversity array) radar, the phase difference between different element of echo was dependent on both range and angle，which implies that the false targets could be suppressed due to the mismatch in either range or angle. The phase difference formula of echo, jamming and mixed signal were derived, the influence on the phase difference of matched filtering, frequency shift and signal mixing was analyzed in detailed, and the entire identifiable process was introduced . The effectiveness of our proposed scheme in suppressing jamming was demonstrated via theoretical analysis and computer simulations. Results show that the proposed method can discriminate false targets successfully in different scenarios and has a better environmental adaptation.