The invention discloses a molecular spectrum imaging device applied in clinical medicine, biology, hylology, microelectronics and other subject fields. The invention is characterized in that: light sources are connected to dispersion units through optical fibers; the dispersion units are connected to a dark field optical collector through optical fibers and used for illumination of a microscope; a signal of an image sensor CCD is connected to a computer through a cable; a control wire of the computer is connected to a dispersion unit controller which is connected to the dispersion units; the computer changes the wavelength of the light sources through control of the dispersion units, acquires image data through the image sensor CCD and finally obtains molecular spectrum data of a sample. The molecular spectrum imaging device has high technical index and quick imaging speed, does not need a push-broom component, is easy to be combined with the general microscope for use and has wide imaging spectrum range covering visible light and near infrared light, thereby being favorable for detection and analysis of biological tissues.