A Global Positioning System On The Air testing method, comprising: 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; rotating the rotating table to pass the terminal under test through each angle, and, at each of angles, switching a polarization direction of a testing antenna in the darkroom; acquiring a satellite signal strength at each of the angles and in each of polarization directions, and forming a signal strength direction map according to the satellite signal strength; searching for an optimal angle and an optimal polarization direction according to the signal strength direction map, acquiring a signal to noise ratio value corresponding to the optimal angle and the optimal polarization direction, and acquiring a sensitivity corresponding to the optimal angle and the optimal polarization direction according to the SNR value; acquiring a sensitivity at each of the angles according to the sensitivity corresponding to the optimal angle and the optimal polarization direction and according to the signal strength direction map; and acquiring an antenna signal strength according to sensitivities corresponding to all the angles and the polarization directions; wherein the optimal angle and the optimal polarization direction are an angle and a direction which give an optimal satellite signal strength, and the angles include oblique angles and azimuth angles; the method being characterized in that the acquiring a sensitivity corresponding to the optimal angle and the optimal polarization direction according to the SNR value, satisfies a following relationship: EIS EUT = EIS GS + CN GS − CN EUT where, EIS GS represents a sensitivity of a reference terminal when being tested at the optimal angle and in the optimal polarization direction in a standard darkroom, CN GS represents an optimal SNR value of the reference terminal obtained in the current darkroom, CN EUT represents the SNR value of the terminal under test corresponding to the optimal angle and the optimal polarization direction in the current darkroom, and EIS EUT represents the sensitivity of the terminal under test corresponding to the optimal angle and the optimal polarization direction in the current darkroom. 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; rotating the rotating table to pass the terminal under test through each angle, and, at each of angles, switching a polarization direction of a testing antenna in the darkroom; acquiring a satellite signal strength at each of the angles and in each of polarization directions, and forming a signal strength direction map according to the satellite signal strength; searching for an optimal angle and an optimal polarization direction according to the signal strength direction map, acquiring a signal to noise ratio value corresponding to the optimal angle and the optimal polarization direction, and acquiring a sensitivity corresponding to the optimal angle and the optimal polarization direction according to the SNR value; acquiring a sensitivity at each of the angles according to the sensitivity corresponding to the optimal angle and the optimal polarization direction and according to the signal strength direction map; and acquiring an antenna signal strength according to sensitivities corresponding to all the angles and the polarization directions; wherein the optimal angle and the optimal polarization direction are an angle and a direction which give an optimal satellite signal strength, and the angles include oblique angles and azimuth angles; the method being characterized in that the acquiring a sensitivity corresponding to the optimal angle and the optimal polarization direction according to the SNR value, satisfies a following relationship: