The invention relates to an optical fiber adapter comprising an adapter shell. A sleeve of which the axis extends along the left-right direction is arranged inside the adapter shell. The left end of the adapter shell and the sleeve is a left plug end for a first optical fiber plug to be plugged into. The right end of the adapter shell and the sleeve is a right plug end for a second optical fiber plug to be plugged into. At least one plug end is equipped with a sealing ring used for being in seal fit with the corresponding optical fiber plug. Through the sealing rings, the corresponding optical fiber plugs can be plugged into the optical fiber adapter in a sealed manner, it is ensured that the optical fiber adapter has a waterproof and dustproof sealing function after the corresponding optical fiber plugs are plugged, and the optical fiber adapter can be used in occasions with waterproof and dustproof requirements.