The present disclosure relates to an acoustic output device. The acoustic output device comprises a housing and an air-conduction vibrator. The air-conduction vibrator is disposed in the housing. The housing includes a first acoustic chamber and a second acoustic chamber. The first acoustic chamber and the second acoustic chamber are located on two sides of a diaphragm of the air-conduction vibrator, respectively. The housing is provided with a sound outlet hole and a first pressure relief hole. The sound outlet hole is in communication with the first acoustic chamber, and the first pressure relief hole is in communication with the second acoustic chamber.