In this paper， a new method for horizontal dynamic positioning control of underactuated Autonomous Underwater Vehicle(AUV)is proposed. According to the actuating mechanism configuration of the self-developed AUV platform，a motion controller has been designed to adjust the longitudinal thrust and bow torque. After two stages of path tracking and zone stabilization，the AUV fast approaches the target point along the preset path first，then gradually adjusts the horizontal position at low speed，and finally keeps hovering in a small range near the point. Combined with the experimental data，it has been proved that the AUV can reach and stabilize within 2 meters near the target point，and can return after being deviated by the external force disturbance，thus verifying the effectiveness of the dynamic positioning control strategy.
