现代舰艇通常装备有多部声呐，对这些声呐的检测信息进行融合，并加以综合利用，以提高整个声呐系统对目标的定位精度具有重要的现实意义．本文利用ＥＭ（Ｅｘｐｅｃｔａｔｉｏｎ Ｍａｘｉｍｉｚａｔｉｏｎ）算法，对多部声呐检测的方位信息进行了数据融合，获得了满意的结果．该算法也可应用于其他水下定位系统 Modern naval vessels are usually equipped with multiple sonars. The fusion of these sonar detection information and its comprehensive utilization make it of great practical significance to improve the positioning accuracy of the entire sonar system. In this paper, we use EM (Expectation Maximization) algorithm to obtain the satisfactory results by the data fusion of the position information detected by multiple sonars. The algorithm can also be applied to other underwater positioning systems