Abstract: Presents a new full-digital feed-forward auto gain contnol(AGC) algorithm aiming at the problem that the digital jam eliminations outputs have large dynamic range in the anti-jamming navigation receiver. Studies all parameters of setting methods and points out the field programmable gate array(FPGA) implementation tips. In order to make outputs reach the anticipated ranges, only one-step gain adjustment is needed. Simulations indicate that appropriate gain control factor precision ensures the performance of full-digital feed-forward AGC for various virtual-bit inputs.