Abstract: A new accurate test method for circular polarized antenna is proposed in this paper, which uses only the amplitude pattern in the test to calculate the characters of the relative polarization ellipse, and then, the main polarization pattern, cross polarization pattern, axial ratio (AR) pattern can be obtained. By using this new antenna test method and the time domain hardware-gating test technique, a large UHF band helix antenna has been tested in a compensated compact range (CCR) successfully and the ideal test results were obtained. That makes it possible for CCR’s dual reflectors system to be used in UHF frequency band.