The invention provides a Ku/Ka frequency band circularly polarization integrated receiving and transmitting feed source antenna applied to antenna systems, such as a paraboloid antenna and the like, in satellite communication. The antenna adopts a coaxial nested compact structure, and is applied to Ku frequency band and Ka frequency band at the same time. The basic structure of a feed source comprises a circular waveguide, on which a pointed cone shaped dielectric rod is loaded, a flange, a coaxial waveguide, a symmetrical SMA connector pair, a circular polarizer and an orthogonal mode coupler, wherein the feed source in the Ka frequency band is applied to dual circular polarization, has rotary symmetrical radiation directional diagrams, the circularly polarization axial ratio in Ka double band is smaller than minus 2dB, and the transmitter-receiver isolation is smaller than minus 70dB; and the feed source in the Ku frequency band is applied to dual circular polarization, has rotary symmetrical radiation directional diagrams, a cross polarization level smaller than minus 40dB, and good transmitter-receiver isolation and reflection loss.