An optical cable connection box (1) with an auxiliary device for gap filling and waterproofing is provided. The connection box includes at least one cable accessing end face (2), at least one auxiliary device for gap filling and waterproofing and at least one elastic shrinkable tube (4). The end face (2) is provided with a first hollow tubular column (3), and an optical cable to be waterproof processed by the elastic shrinkable tube (4) passes through the hollow tubular column (3) in the form of dual cable (5) after face to face bending, so that cable halfway splitting and halfway branching can be processed in the box without cutting off the cable. The auxiliary device cooperates with the optical cable in the hollow tubular column (3), and a first waterproof structure is formed at the place where the auxiliary device is wrapped by the elastic shrinkable tube (4). At least the outside of the first hollow tubular column (3) and at least a portion of the auxiliary device are also wrapped by the elastic shrinkable tube (4) to form a second waterproof structure. The connection box provides a better waterproof effect and reduced cost.