The underwater acoustic sensor network localization technology is researched in this paper. Aiming at the problem of low node location precision, an adaptive weighted node localization algorithm for underwater acoustic sensor networks is proposed. Considering the ranging error of the underwater acoustic sensor network nodes increasing with the increase of the distance between nodes, the algorithm improves the anchor node selection mechanism, and weights the different anchor nodes in the location measurement, improves location measure, and increases the utilization rate of measured information. Simulation experiment results show that this algorithm can improve the localization accuracy.