Abstract: The profile of a two-dimensional axi-symmetric inhomogeneous medium is reconstructed by using the distorted Born iterative method and multi-grid technique. In the previous inversion procedure, we consider the whole objective area as one grid, and the mean value of the objective function is obtained approximately by the distorted Born iterative method; then the size of the discretization grid inside object gradually is reduced, the results reconstructed in the last level grid is used as new background medium and the profile reconstruction of the objects is solved continuously by the distorted Born iterative method. The numerical examples show that the new method has the robust feature, the computational time of the inversion procedure is reduced vastly and more accurate inversion results of the higher-contrast scattering objects can be obtained.