The invention discloses an optically annular lighting device, and relates to a lighting device. The optically annular lighting device is provided with a mechanical adjusting frame, a first fixing frame, an inner
conical surface reflecting mirror, a
conical surface reflecting mirror and a second fixing frame, wherein the mechanical adjusting frame is internally provided with a
screw thread, the first fixing frame and the second fixing frame are embedded into the mechanical adjusting frame, the inner
conical surface reflecting mirror is fixed on the first fixing frame, and the conical surface reflecting mirror is fixed on the second fixing frame. According to the invention, the energy of an emergent annular
light beam basically has no loss compared with that of an incident light
ray; the optically annular lighting device basically has no phenomena such as chromatic dispersion,
spherical aberration and has a wide range of working wavelengths; the structure of the conical surface reflecting mirror is simple and is easy to process; and the optically annular lighting device can be matched with any objective lens with different backlight aperture sizes, can continuously adjust the angle of an incident excited light and the line
diameter size of the emergent annular
light beam, and is suitable for the fields of
fluorescent light and Raman experiment researches such as
high angle SPR (
surface Plasmon resonance) excitation, ATR (attenuated total reflectance), super-resolution optical microscopes and the occasions such as advertisement demonstration, stage demonstration.