Abstract Acousto‐optic (AO) devices are known for their high parallel processing capabilities and efficient transduction, essential for real‐time processing systems. As a vital AO medium, chalcogenide glasses exhibit high AO figures of merit (M 2 ), yet high M 2 is often coupled with high acoustic attenuation (α). Thus, to obtain the trade‐off between M 2 and α, a series of x GeSe 2 −(100− x )Sb 2 Se 3 (40 ≤ x ≤ 85) is investigated for their AO properties. When GeSe 2 content reaches 50%, a stable network of [GeSe 4 ] and [Se 2 Sb–Se–SbSe 2 ] units forms, minimizing energy loss and α while maintaining a high M 2 . Compared with conventional AO materials, this composition achieves an exceptional equilibrium between high M 2 and reduced α, offering a distinct advantage in optimizing performance. This unique composition balance provides valuable insights for developing advanced chalcogenide glasses in AO applications.