The utility model provides a high-frequency
monochromator, which is characterized by comprising a
spectrograph and a scanning emitting mechanism, and the scanning emitting mechanism is loaded after the
spectrograph emits a
light beam. An entrance slit, a
spectrograph, a field diaphragm, a collimation optical
assembly, a rotary reflector or a rotary reflector with a
grating light splitting function, a convergence imaging
assembly and an exit slit are sequentially arranged along a light path, and light is emitted through the field diaphragm and the exit slit to form an L-shaped light path; the entrance slit, the spectrograph, the field diaphragm, the collimation optical
assembly, the rotary reflecting mirror or the rotary reflecting mirror with the
grating light splitting function, the convergence imaging assembly and the exit slit are all vertically fixed to the horizontal plane, and the rotary reflecting mirror or the rotary reflecting mirror with the
grating light splitting function is arranged at the switching position of the L-shaped light path; the
monochromator is simple in light splitting structure and efficient in light splitting.