Abstract: Generalized ridge estimate was suggested for solving the ill-posed problem in downward continuation (DWC) of airborne gravity, three regularization methods were studied to solve the inverse Poisson problem, which are Tikhonov regularization, ridge estimate and generalized ridge estimate. By conducting a simulated numerical experiment designed based on EGM2008 Earth gravitational model, the 2.5′×2.5′gravity disturbances with white noise at the flight levels were downward continued to the Geoid, the accuracy and stability of the DWC methods were tested and compared, the numerical results show that, in terms of continued accuracy, stability and robustness, the generalized ridge estimate based on multiple optimal regularization parameters performs significantly better than Tikhonov regularization and ridge estimate which based on single regularization parameter.