Abstract: For unstablity and unreliability of the traditional nonlinear least squares solution of ill-conditioned problems, a Frozen-Barycentre iterative algorithm is proposed based on the least squares solution property of nonlinear ranging location. The method applies the Samaski technique to Barycentre iterative method, to realize the transformation of internal and external iterations. This algorithm improves the convergence efficiency of Barycentre iterative method by reducing the derivative calculation. And the numerical convergence experiments of the method are performed. The results show that the numerical precision of proposed method is better than that of the linearized adjustment estimation, and the convergence property is more efficient than the Barycentre iterative method.