Abstract: In this paper,the distorted born iterative method(DBIM) is applied to deal with the inversion problem of the short normal device measurements in two-dimensional axisymmetric medium.In each iteration of the DBIM,an effiecient-half analytical half numerical method is used to solve the problem.This method provides a semianlytic expression for the Green's function and its derivatives required in the inversion,and then deduces a semianalytic expression of the integration in the nonlinear intergral equation.Therefore,the efficiency and accuracy are improved dramatically.