Abstract: The present disclosure discloses an in-ear earplug structure, which comprises a hollow support body, wherein a sound hole is opened at a front end of the support body, an outer side of the support body is provided with at least two soft umbrella-shaped plug bodies, the support body and the umbrella-shaped plug bodies are integrally molded, a speaker unit is provided in the support body, a preset spacing is formed between the speaker unit and the sound hole, a rear sound cavity is formed in the support body, the rear sound cavity is located on the rear side of the speaker unit, and a through hole which is in communication with the rear sound cavity is opened at a side part of the support body. In the above structure, when the earplug is worn on an ear, the hard feeling caused by the earplug is greatly reduced, and the wearing comfort is effectively improved. Also, this makes the umbrella-shaped plug body better fit an ear canal, thereby improving the sound insulation effect.