Aim at the problem of GPS deception jamming about navigation countermeasure, based on feasibility analysis for implementing GPS repeater deception to GPS guidance target, repeater time-delay decision model is established, and the repeater time-delay algorithm is deduced. Meanwhile, the clock-offsets difference after the deception jamming is analyzed and the approach of reducing the clock-offsets difference is given. Finally, according to the simulation, the validity of repeater time-delay algorithm is testified and the jamming targets which use four-station and single-station repeater are given.