A general linearization iteration (GL1) inversion method is adapted to invert the NMR of a layered electrical conductive media. In the case of electrical conductive earth, Jacobian matrix can be estimated analytically. The flattest and smoothest model constraints are imposed to the optimization problem. A true model is inverted from field data with GLI inversion. GLI inversion method of surface NMR converges fast and stably, and is applicable to layered electrical conductive earth.