Abstract: We investigate the secrecy rate optimization problem in a wiretap channel with a single-antenna source, a single-antenna eavesdropper, and a multiple-antenna full-duplex (FD) destination. We design a near-optimal joint optimization algorithm by jointly applying the dynamic antenna mode switching (AMS) and optimal power allocation (OPA) techniques, to maximize the secrecy rate of FD destination-based jamming (DBJ) system. Specifically, a closed-form of OPA factor is first derived using global instantaneous channel state information (CSI), and then the optimal transmit and receive antennas sets at the destination are determined by combining the OPA factor and applying a greedy search-based approach. Simulation results verify the secrecy performance superiority of the proposed algorithm over the traditional FD-DBJ method.