The invention discloses a vent structure, a washing machine and a control method, and relates to the technical field of washing machines. The vent structure comprises a vent and a rotating body, wherein the vent is formed in a to-be-vented device and communicated with a chamber in the to-be-vented device; the rotating body is rotationally arranged at the vent, and a first connecting hole is formedin the rotating body in the radial direction in a penetrating manner and can be selectively communicated with the vent. According to the vent structure, the vent can be blocked or the connecting holein the rotating body can be communicated with the vent through rotation of the rotating body, so that the vent is selectively opened or closed; when the washing machine is in a washing state, the rotating body blocks the vent to prevent heat or washing water from being sprayed out of the vent, so that heat loss is prevented and burning of users is avoided; after washing of the washing machine iscompleted, the rotating body rotates to enable the connecting hole to be communicated with the vent, the inside and outside of the washing machine are communicated, moisture is discharged from the vent, and accordingly, mildew and peculiar smell of the washing machine or clothes in the washing machine are prevented.