In view of the problems existing in search and rescue at sea by Coast Guard, this paper, with the OODA Loop theory as the framework, analyzes the four critical elements of search and rescue at sea, namely Observation, Orientation, Decision and Action, to build a command system model for search and rescue at sea. Combined with the distress alarm information, the search and rescue operation monitoring network is constructed to obtain timely and comprehensive observation information elements. It is developed to search and rescue simulation according to the search and rescue action plan, tested and verified for the search and rescue plan, and verified for the command process. In order to improve the efficiency of maritime search and rescue, some measures should be taken such as to improve the performance of search equipment and build professional rescue forces. This research can serve as significant reference for improving the efficiency of the search and rescue at sea.