Aiming at the problem that the existing underwater wireless sensor network positioning algorithm has insufficient positioning accuracy and cannot adapt to the underwater changeable network topology, an underwater wireless sensor network positioning algorithm based on mobile beacon is proposed. Firstly, RSSI ranging positioning and DV-Hop algorithm are used to obtain the approximate distribution of unknown nodes. Secondly, taking the positioning coverage rate of unknown nodes as the objective function, the improved bald eagle search algorithm optimized by adaptive inertia weight and Cauchy-t disturbance strategy is used to iteratively solve the optimal position of beacon node movement. Finally, the beacon node moves to the optimal position and then the unknown node is repositioned. The simulation results show that compared with the comparison algorithm, the mobile beacon node localization algorithm can effectively improve the positioning accuracy of unknown nodes, and can also maintain high positioning accuracy and stable positioning effect when the network topology changes.