For unstabily and unreliability of the traditional nonlinear least squares solution of ill-conditioned problems, a regularization homotopy method is proposed for solving distance equation based on the homotopy mapping theory. Moreover, a geometric descending function is adopted to adjust the regularization parameter. The efficiency and the stability of computation procedure were highly improved by using this function. Finally, the numerical convergence experiments of the method are performed. The result show that the regularization homotopy method can deal with the distance equations stably and rapidly.