Abstract: To address the issue of the relatively large stowage height and low system flexibility of traditional mediem-aperture dual-reflector antennas.This paper takes a dual-reflector antenna with an equivalent diameter of 3 meters as an example, and introduces a structural form for a medium-sized aperture vehicle-mounted antenna to achieve a low-profile stowable. This antenna adopts a special form of dual-reflector structure. Its main reflector is composed of a flat reflective panel with an elliptical shape and the secondary reflector is a single-biased parabolic reflector. This structuralform enables it to achieve a significant extension-retraction ratio in terms of its height dimension. It can be installed on various vehiche carriers and meets the requirements for transportation height. Through simulation verification, the structural strength of this antenna is found to be safe and reliable, and it can meet various working conditions of the vehicle-mounted antenna.