Disclosed is an earphone comprising a loudspeaker unit, an audio signal wire electrically connected to the loudspeaker unit, and an auxiliary structure; the auxiliary structure comprises a front cover and a housing; a front acoustic cavity is defined as a space between the front cover and the loudspeaker unit, and a rear acoustic cavity is defined as a space between the housing and the loudspeaker unit; an acoustic guide channel capable of enhancing low-frequency performance of the earphone is disposed on one side of an inner sidewall of the housing closer to the loudspeaker unit; the acoustic guide channel comprises an open end and a closed end, and a bottom wall of the acoustic guide channel is provided with a plurality of through holes at a position closer to the closed end. An earphone with this structure improves low-frequency and middle-frequency sound effects of products, and makes the earphone have a good appearance.