The utility model discloses a casing for melting distribution integral units, which is a cuboid, surfaces of the casing are equipped with a plurality of holes with different sizes, and the casing is internally equipped with a plurality of sets of weld distribution discs and fixing devices comprising optical cable fixing clamps and optical cable steel stranded wire fixing clamps. The casing is characterized in that the length of a cable inlet hole on the rear end of the lateral surface of the casing ranges from 10cm to 15 cm, and the width ranges from 3 cm to 6 cm. The casing of the utility model can be in front-and-rear double-surface operation, conditions in the case during constructing can be directly learnt , thereby bringing convenience for construction operation and maintenance, reducing bend angle of optical fibers, and further avoiding loss for bending. Expandable activity space of the optical fibers in the holes is increased, thereby reducing the friction of the optical fibers after poking and edges of the holes, and reducing broken fibers.