The invention discloses a feed source apparatus for a fan antenna. The feed source apparatus comprises a feed source base, a radiation horn and a transmission waveguide, and is characterized in that the transmission waveguide is fastened on the feed source base through fasteners, a radiation head is arranged above the radiation horn, and the radiation horn and the radiation head are locked on the transmission waveguide through fasteners. The structure is simple, and use and installation are convenient. Compared with similar products, the feed source apparatus has better performance.