Abstract: The transparent terahertz wave absorber can not only realize the absorbing function in the terahertz band, but also be transparent to visible light and has high concealment. Therefore, it has a wide range of applications in electromagnetic stealth and other fields. In this paper, a terahertz dual-frequency absorber based on graphene is designed. The absorber consists of a square-shaped and branch-shaped graphene upper-layer broadband absorber structure and a graphene-ITO nested lower-layer narrow-band absorber structure. It has independently adjustable dual-frequency absorbing function. Through simulation debugging, the absorber can adjust the graphene Fermi energy to achieve a wide-band absorption rate of more than 90% in the range of 1. 98-3. 64 THz and adjust the center frequency absorption rate of more than 96% in the range of 4. 6-4. 9 THz. It verifies that the absorber has the advantages of polarization insensitivity and wide incidence range.