An optical fiber adapter includes a main body, an inner housing, a movable shutter, a latch element, a spring and a cover. The inner housing is disposed in an axial accommodation room of the main body. The movable shutter includes a shutter portion, a pivot portion and a first interference structure. The first interference structure is disposed on the pivot portion, the pivot portion is rotatably disposed in the axial accommodation room, and the shutter portion placed in front of the hollow cylinder of the inner housing. The latch element includes a pushed portion, a cantilever portion and a second interference structure. The latch element is linearly movable in the axial accommodation room. The spring is disposed in the axial accommodation room and abuts against the latch element. The optical fiber adapter may shield high-intensity light by using movable shutter to protect eyes from damage.