The present invention achieves multiplexing spectrum interference optical coherence tomography capable of full-range OCT measurement that causes no delays in measurement time due to high-order scans and is also free from complex conjugated images. This multiplexing spectrum interference optical coherence tomography comprises: a first beam splitter 3 positioned in an optical path 2 from a light source 1 and used to separate an object light 4 and a reference light 5; a galvano mirror 6 positioned in the optical path of the object light 4 and used to scan the object light onto a measured object 8; a second beam splitter 10 positioned in the optical path of the reference light 5; a first reference mirror 12 positioned in the optical path of a first reference light 11 separated by the second beam splitter 10; a second reference mirror 15 positioned in the optical path of a second reference light 13 separated by the second beam splitter 10; and a chopper 16 that passes the first reference light 11 and second reference light 13 alternately.