A thermoacoustic device includes a carbon nanotube composite structure, a sound wave generator and a signal input device. The carbon nanotube composite structure includes a carbon nanotube structure and a matrix. The matrix is located a surface of the carbon nanotube structure. The sound wave generator is located on a surface of the carbon nanotube composite structure and insulated from the carbon nanotube structure via the matrix. The sound wave generator includes a graphene layer including at least one graphene. The signal input device is configured to input signals to the sound wave generator.