Focusing-type optical wavelength division multiplexer

The invention relates to a focusing-type optical wavelength division multiplexer comprising a metal shell having an inner cavity. An optical filter, parallel optical lenses and a glass capillary are mounted in order within the metal shell. A capillary protective sleeve sleeves the glass capillary. A metal positioning ring sleeves the parallel optical lenses and is tightly fitly connected with the wall of the inner cavity of the metal shell. One end, close to the optical filter, of the metal positioning ring is circularly provided with a circular 45-degree slope structure from inside to outside. A focusing lens is connected to the outer end of the optical filter. The focusing-type optical wavelength division multiplexer is simple in structure, high in coaxiality, stable and reliable in performance, simple to produce and mainly applicable to the field of optical communications and has good practical application value.