The invention discloses a wavelength division multiplexer steel tube shell with incoming and outgoing line packaging structures, which comprises a steel tube shell and an incoming and outgoing line packaging structure, the number of the incoming and outgoing line packaging structures is two, the two incoming and outgoing line packaging structures are movably inserted into the left side and the right side of the steel tube shell respectively, the steel tube shell comprises an inner shell and an outer shell, the outer shell is sleeved outside the inner shell, and a rubber layer is arranged between the outer shell and the inner shell. The beneficial effects are that double shells are adopted, the double shells are filled with the rubber layer therebetween, and the impact resistance is strong;the inner side of the inner shell is provided with a coating film, and the isolation performance of a wavelength division multiplexer is enhanced; the inner shell and the outer shell are provided with bulges, so that the relative stability of the inner shell and the outer shell is ensured; the incoming and outgoing line packaging structure adopts a top ring to extrude a rubber ring so as to achieve a purpose of enabling the rubber ring to package an optical fiber head, and the packaging is performed conveniently; and a side cover is enabled to be fixed on a cylindrical body due to a mutual extrusion effect of the top ring and the rubber ring when the side cover is inserted into the steel tube shell, other fixation modes are not required, and the assembly and disassembly are performed conveniently.