Since the 21st century, with the continuous improvement in human living standards, the problems
of global climate change, rapid population growth, and environmental pollution have become
increasingly serious.The main water quality parameters include chemical oxygen demand (COD), heavy
metal content, nitrate nitrogen (NO3-N), dissolved organic carbon (DOC), and turbidity.In 
addition, the research progress on the determination of COD, heavy metal ions, nitrate nitrogen, 
and DOC by UV-Vis spectroscopy was described in detail.In recent years, due to the advantages of high precision, high detection efficiency, 
nondestructive sampling, environmental protection, low cost, and portability, ultraviolet-visible 
(UV-Vis) technology combined with a variety of advanced technologies has developed into an 
excellent and effective tool for detecting pollutants in aqueous environments [7].In recent years, due to the advantages of high precision, high detection efficiency, nondestructive
sampling, environmental protection, low cost, and portability, ultraviolet-visible (UV-Vis) technology
combined with a variety of advanced technologies has developed into an excellent and effective tool
for detecting pollutants in aqueous environments [7].This paper introduced the theoretical basis of determining various water quality parameters by 
UV-Vis spectroscopy and expounds the complete spectral data analysis process, including data 
preprocessing (Section 3.1), extraction of the characteristic wavelength (Section 3.2), establishment 
of absorbance and relevant water quality parameter model (Section 3.3), as shown in Figure 2.This paper introduced the theoretical basis of determining various water quality parameters
by UV-Vis spectroscopy and expounds the complete spectral data analysis process, including data
preprocessing (Section 3.1), extraction of the characteristic wavelength (Section 3.2), establishment of
absorbance and relevant water quality parameter model (Section 3.3), as shown in Figure 2.UV-Vis spectrum 
analysis is an important development direction for water quality monitoring, which evaluates the 
degree of water pollution by establishing a correlation model of absorbance, organic matter, and 
inorganic matter concentration (Section 3.3) [8].UV-Vis spectrum analysis is an important
development direction for water quality monitoring, which evaluates the degree of water pollution by
establishing a correlation model of absorbance, organic matter, and inorganic matter concentration
(Section 3.3) [8].Spectroscopy is a method to identify substances and conduct quantitative
determination through the emission or absorption spectra of substances, which have been frequently
used in the field of rapid water quality determination in recent years [6].Spectroscopy is a method to identify 
substances and conduct quantitative determination through the emission or absorption spectra of 
substances, which have been frequently used in the field of rapid water quality determination in 
recent years [6].Although some researchers have tried to summarize the field before [9], with the deepening of 
UV-Vis spectroscopy in this field of water quality detection, its research objects and research 
methods have also undergone tremendous changes.Although some researchers have tried to summarize the field before [9], with the deepening of
UV-Vis spectroscopy in this field of water quality detection, its research objects and research methods
have also undergone tremendous changes.With rapid social development
and the increasing use of agricultural fertilizers, an increasing number of industrial pollutants are
discharged into rivers and oceans, causing eutrophication.For example, Giudicianni et al. [10] used 
principal component analysis (PCA) and wavelet transform to calculate water quality index.Sci.Sci.