The invention relates to a regional optimal solution algorithm for underwater moving target precise positioning, which comprises the steps that underwater sensor nodes are deployed, and location information of the nodes is acquired; an activation threshold of the nodes is set, and the nodes are enabled to initially stay at a dormant state; each dormant node periodically judges whether to turn into an activated state or not; the nodes, which stay at the activated state, send marked acoustic waves so as to carry out detection on a target; the node, whose residual energy is the highest, in the activated nodes is searched so as to act as an underwater data processing center, and the other three groups of target information are received to form a positioning equation set so as to solve the target location; a regional optimal solution algorithm is defined to solve a circumstance of intersection regions occurred in a large number of positioning equation sets appeared in reality, and an acquired optimal solution is enabled to act as the target position acquired by the positioning equation set at the moment; and the activated node returns back to the dormant state if not satisfying node activation conditions in five continuous periods. The regional optimal solution algorithm provided by the invention has the advantages of ability of improving the data utilization rate of a sensor network, high positioning precision, low energy consumption and the like.