The deployment of underwater sensor nodes is the basic work for the application of underwater sensor networks. A good deployment scheme of sensor nodes can effectively improve the monitoring quality of targets. In view of the high dynamic and uncertain characteristics of random events in the water environment, an optimal deployment scheme of underwater sensors networks based on self-organizing map algorithm is proposed. Firstly, the sensors are deployed randomly, and the random events are assumed to be unevenly distributed in L shape. When a random event occurs at the blind area, the self-organizing map algorithm is used to determine the target position to which the underwater sensor needs to move. The simulation results show that the optimal deployment scheme of underwater sensors networks based on self-organizing map algorithm can significantly improve the coverage of random events and achieve effective monitoring of the water environment.