The invention provides an 8-shaped like planar broadband circularly polarized antenna. The planar broadband circularly polarized antenna comprises a dielectric substrate, a top-layer radiation unit and a bottom-layer radiation unit, wherein the top-layer radiation unit is arranged on an upper surface of the dielectric substrate; the bottom-layer radiation unit is arranged on a lower surface of the dielectric substrate; the top-layer radiation unit and the bottom-layer radiation unit are the same in sizes and structures; the top-layer radiation unit consists of a top-layer metal strip radiation unit and a top-layer metal half-wave dipole unit which are connected with each other; the bottom-layer radiation unit consists of a bottom-layer metal strip radiation unit and a bottom-layer metal half-wave dipole unit which are connected with each other; and the top-layer radiation unit and the bottom-layer radiation unit are arranged in an inversesymmetry way like the number 8 relative to the dielectric substrate. The structure is suitable for the broadband circularly polarized antenna. Through adoption of the 8-shaped like planar broadband circularly polarized antenna, the antenna structure is symmetric and simple; convenientfeed is achieved; and broadband wide-beam circularly polarized radiation can be realized. Moreover, the antenna is small in size, and low in manufacturing cost.