Our company has raised 1.5 million yuan on its own, and an additional 1.5 million yuan is needed for national subsidies. The complex composition of wastewater requires classification and detection when using spectral method for water quality parameter detection. The difficulty lies in the implementation of detection and the mathematical models required for parameter calculation. Explore the specific absorbance wavelengths of each water quality parameter through specific experiments, and establish a mathematical model to compensate for the algorithm between each other's parameters. Establish characteristic absorption spectra of water quality with multiple parameters. Developed a spectroscopic multi-parameter water quality online analyzer, which uses spectroscopic methods to detect various pollutants such as COD, BOD, TOC, SAC254, nitrate, nitrite, turbidity, chromaticity, suspended solids, and other parameters in water. In recent years, China's water bodies have been facing increasingly severe pollution problems, which have caused enormous pressure on human production, life, and sustainable development of the ecological environment. In order to quickly and effectively monitor the water quality, this paper, based on spectroscopy, measured the ultraviolet visible near infrared absorbance of untreated water, and qualitatively and quantitatively analyzed the type and content of impurities in the water. And compared to traditional chemical methods, it does not generate secondary pollution and is a good detection method for maintaining sustainable environmental development at present and in the future.