A GPS OTA testing method and system is provided. The GPS OTA testing method comprises: placing a terminal under test on a rotating table in a darkroom, and generating a GPS signal by a GPS satellite signal generator in the darkroom; acquiring the satellite signal strength at each of the angles and in each of the polarization directions, and forming a signal strength direction map; searching for an optimal angle and an optimal polarization direction and acquiring a sensitivity corresponding to the optical angle and the optimal polarization direction; and acquiring a sensitivity at each of the angles and in each of the polarization directions according to the sensitivity corresponding to the optimal angle and the optimal polarization direction and according to the signal strength direction map and integrating the sensitivities to acquire an antenna signal strength.