Abstract: An aerogel-loaded ultra-wideband high temperature resistant composite dielectric resonant antenna for hypersonic vehicles is presented in this paper. Above the antenna substrate, from bottom to top, is the dielectric resonant antenna 1, the dielectric resonant antenna 2 and the dielectric lens, which are connected with the dielectric resonant antenna 2 by a circular dielectric rod, and they are embedded in the aerogel. A microstrip slot-coupled feed structure is used to excite the working modes with similar frequencies in the double-layer composite dielectric resonant antenna and merge them successfully. The final antenna operates from 4. 8 GHz~ 10. 4 GHz, and the relative bandwidth reaches 73. 7%. The final antenna works from 4. 8 GHz ~ 10. 4 GHz, and the relative bandwidth reaches 73. 7%. The antenna uses high temperature resistant dielectric material and loads high temperature resistant aerogel outside the structure to realize the integrated design of antenna and heat insulation material, which makes the antenna profile height only 0. 76 λ0 . The dielectric len not only solves the problem of main lobe cracking of antenna pattern, but also effectively improves the antenna gain. The maximum gain can be increased by 1. 7 dBi, and the maximum gain of the antenna can reach 9. 2 dBi in the working frequency band. By studying and analyzing the overall heat conduction process of the antenna under aerogel loading, the antenna structure and feed position are optimized and adjusted to further improve the working time of the antenna. The final simulation results show that the antenna can work normally in a high temperature environment of 1 000 ℃ for 1 280 s, and the insulation time is 16% higher than that of aerogel of the same size.