Abstract: Very high frequency omnidirectional range (VOR) is an important radio signal in the field of aviation navigation, and its phase parameters are used to characterize the bearing information. In this paper, the basic principle of VOR signal and the measurement method of azimuth are introduced, and the comparison results of VOR phase parameters in 6 reference laboratories in China are given. The evaluation of domestic VOR phase parameter measurement capability is completed, which lays a foundation for ensuring the uniformity of quantity and value of aviation navigation parameters in China.