The invention provides a headset device. The headset device includes a first headset, a second headset, and a transmission line. The first headset includes a first housing; an interface module for receiving an audio signal; a signal processing module for separating the audio signal into a first channel signal and a second channel signal; an amplifying circuit for respectively amplifying the first channel signal and the second channel signal to generate a first amplified signal and a second amplified signal; and a first speaker for outputting audio according to the first amplified signal. The second headset includes a second housing, and a second speaker for outputting audio according to the second amplified signal. The transmission line is for transmitting the second amplified signal to the second headset.