Abstract: This paper proposes a design method for a continuous field of view multi-beam feed with a common aperture. On the premise of satisfying a high overlap level, the aperture sharing is realized by using the current continuity of tight coupling unit with small size, so as to obtain aperture range which is larger than physical size. The Vivaldi antenna is designed to verify its feasibility as a high-efficiency reflector feed, and the design method of this common-aperture multi-beam feed is summarized when the reflector aspect ratio and illumination angle are fixed. Finally, according to the requirements of the 15 m antenna design index, a Vivaldi feed array is designed, and the array parameters are optimized by using the differential evolution algorithm to achieve a beam coverage of 2°×2° in one octave. The aperture efficiency is above 60%, and the overlap level is within 3 dB.