Abstract: On account of the defects of rigid localization condition and low localization accuracy in double-vessel localization,the paper gives an algorithm of multiple-vessel localization based on weighted least squares.On the theory of bearing cross localization,the algorithm puts forward nonlinear equations of bearing and position variables,then convert the nonlinear equations to linear equations,and finally gives multiple-vessel localization algorithm based on least squares theory and considering bearing accuracy factors.With the help of computer simulation,the algorithm is proved to be feasible and of better localization accuracy and bearing accuracy of reconnaissance equipment and initial vessel formation affects the results of localization.