A dual-bands circularly polarized GNSS (Global Satellite Navigation System) antenna with stable phase center in wide angle is proposed in this paper. The antenna employs a stacked air-box structure, four ports with equal amplitudes is used for antenna excitation with 90° phase difference successively, in order to achieve good circularly polarized radiation. By using a symmetry structure and feeding by two four points, which are equal in amplitude and equally spaced in phase, high phase center stability can be obtained in a broad angular domain. The model of the antenna is simulated, and a prototype is fabricated and measured. The measured results in GPS L1, L2 band & BD B1, B2 band show that the antenna beam width is greater than ±36°, and at the same time the stability of the antenna phase center is up to 1.61 mm at the domain range angle -70°~70°, and 3dB axial ratio angles are more than -46°~46°,which indicate that the antenna has great engineering application value.