Aiming at the problem that the quality of measurement information directly affects the performance of cooperative localization of multiple autonomous underwater vehicles (multi-AUV), a design method for the optimal formation configuration of multi-AUV is proposed to select the best measurement information. First, for the two cases of whether the measurement information is correlated with the measurement error, the performance evaluation functions of formation configuration of multi-AUV are established based on the information ellipse area. Second, through in-depth analysis of these functions, the design methods of the optimal formation configuration in two cases are proposed respectively. Subsequently, taking the multi-AUV cooperative localization systems with four-master and five-master as examples, based on the proposed design method, the optimal formation configuration for cooperative localization system of multi-AUV in two cases is studied deeply, and the results show that it is dynamic. Besides, a special formation configuration is proposed for the cooperative localization system of multi-AUV, which is easier to be implemented compared with the optimal formation configuration when the localization performance is almost the same. At last, the simulation experiments verify the correctness of the proposed method and the effectiveness of the proposed special formation configuration.