The Fiber-Optic Chlorophyll Analyzer adopts the principle of the fluorescence method. According to the spectral absorption characteristics of chlorophyll a, the water body is irradiated by a high-energy LED light source, and the chlorophyll a in the water body is excited to generate fluorescence of a specific wavelength, and the concentration of chlorophyll a in the water is measured. The sensor's fiber-optic structure provides excellent repeatability and stability and is less susceptible to ambient light. with automatic cleaning, and a brush to eliminate air bubbles, reduce the impact of contamination on the measurement, make the maintenance cycle longer, and maintain excellent stability for long-term online use.