The invention belongs to the communication and navigation technology field, and concretely relates to a miniature three-frequency dual-circular-polarized antenna. A fixing through hole and a fastening bolt are disposed coaxially in a plumb central line of an upper-layer microstrip patch antenna, a middle-layer microstrip patch antenna, a lower-layer microstrip antenna and a bottom-layer feed network of the antenna. Axes of three first short circuit metalized through holes and the axis of a first feed hole are on the same cylindrical surface with the axis of the fixing through hole being an axis, and the first short circuit metalized through holes and the first feed hole are uniformly distributed on the cylindrical surface in a circumferential manner. The middle-layer microstrip patch antenna is provided with a second feed point. Axes of three second short circuit metalized through holes and the axis of a second feed hole are on the same cylindrical surface with the axis of the fixing through hole being an axis, and the second short circuit metalized through holes and the second feed hole are uniformly distributed on the cylindrical surface in a circumferential manner. The aperture of each first short circuit metalized through hole is equal to the external diameter of a first medium sleeve. The aperture of each second short circuit metalized through hole is equal to the external diameter of a second medium sleeve. The good impedance bandwidth, the good axial ratio bandwidth and the high gain performance are guaranteed, and also miniature and light demands of the size of the antenna are guaranteed.