The instrument is based on total reflection X-ray fluorescence spectroscopy (TXRF), which uses a high-brightness micro-focus fixed target light source to generate an X-ray beam, and uses a vacuum orthogonal back-to-back X-ray artificial multi-layer reflective focusing mirror to reflect the X-rays twice, reducing the energy range of the beam to a very narrow range. This very thin beam will irradiate a flat sample carrier at an extremely small angle (less than 0.1°) and be completely reflected. The sample will emit characteristic fluorescence and be measured by an energy dispersive X-ray detector. Since the distance between the detector and the sample carrier is very short, the fluorescence detection efficiency is very high, and the absorption of X-rays by the air is also reduced.