Despite the rapid development for thermoelectrics (TEs) and aerogels, elastic aerogel TE generators (TEGs) with vertical-type architectures have not been found to harvest heat utilizing vertical temperature difference. Herein, an elastic poly(3,4-ethylenedioxytiophene)-tosylate(PEDOT-Tos)/single-walled carbon nanotube (SWCNT) TE aerogel was fabricated via convenient chemical oxidative polymerization, physical mixing and subsequent freeze-drying process. Then, we report the first elastic TEGs consisting of vertical-type aerogel legs, which not only inherit the advantages of ultralight weight and compressibility of aerogels, but also display high TE performance. The output performance can be conveniently adjusted by the number of legs, the temperature difference and compressive strain. An optimum output power of 1967 nW (output power density of 30.73 mW m) is achieved for the TE generator using 10 unipolar aerogel legs at 50% strain and temperature difference of 50 K. Furthermore, the ultralight and compressible TEG displays excellent capability of harvesting heat under vertical temperature difference and mechanical deformation, such as on hot oil/plate or compression by human body. The results will greatly facilitate the development of TE aerogels and TEGs, and widen the versatile application scenarios.