An acoustic device comprises a shell and a sound producing assembly, the shell being provided with an installation hole and a sound outlet, and the sound producing assembly being fixed inside the shell. The sound producing assembly has a diaphragm separating a cavity of the acoustic device into a front cavity and a back cavity, a first part of the shell corresponding to the front cavity and/or a second part of the shell corresponding to the back cavity is provided with sapphire glass covering the installation hole, and the front cavity is in communication with the outside of the acoustic device through the sound outlet.