The utility model relates to an optical cable beam-splitting fiber-distribution case provided with a rubber-insulated wire fastening device comprising a case body provided with a wire penetrating hole used for the penetration of optical cables. A reel and a fiber splice tray are disposed in the case body. The optical cable beam-splitting fiber-distribution case is characterized in that the rubber-insulated wire fastening device is disposed in the case body, and is disposed between the reel and the wire penetrating hole, and is close to the wire penetrating hole; the rubber-insulated wire fastening device is formed by an upper clamping plate and a lower clamping plate, which are in a detachable connection, are respectively in the rack-structure, and are engaged with each other in an up-down manner correspondingly; the clamping teeth of the upper clamping plate and the lower clamping plate are respectively in the shape of a cuboid; when the upper clamping plate is connected with the lower clamping plate, gaps used for clamping the optical cables can be formed by the lower end surfaces of the clamping teeth of the upper clamping plate and the bottom parts of the tooth grooves of the lower clamping plates. The utility model is advantageous in that by arranging the rubber-insulated wire fastening device in the optical cable beam-splitting fiber-distribution case, the cables can be ordered and fastened, and therefore the optical cables can be beautiful and tidy, and can be effectively prevented from being pulled out at will, the required wiring amount can be achieved, and the safety operation of the devices connected with the optical cables can be protected.