Abstract: In the electronic warfare environment, the accompanying false target can move nonlinearly in the main lobe of radar, which makes it difficult for beam nulling to aim at the false target position in time under the phased array system. To solve this problem, a dynamic nulling technique based on frequency diverse array (FDA) radar is proposed. The system extracts the range information of false target from the environment, and then obtains the extrapolation trajectory of false target by using the extended Karman algorithm combined with cognitive technology, and transmits the prediction information back to the transmit module of radar through feedback. Then the adaptive beamforming in range dimension based on FDA is adopt to adjust the transmit weight vector so that the beam nulling can point to the predicted position of the false target. The simulation results show that the proposed method can effectively achieve the dynamic nulling of the moving false target in the main lobe of radar. It has significant performance advantages compared with adaptive beamforming without prediction information, providing technical support for FDA to resist the main lobe deceptive interference. And it has certain theoretical and practical significance in array signal processing.