Complex monitor for automatically monitoring multiple parameters of water on line

The invention discloses a method for automatically monitoring water quality indexes on line and a device for implementing the method. A method of combining an ultraviolet and visible spectroscopy and various sensors is adopted, dozens of water quality indexes including chemical oxygen demand and ammonia nitrogen can be measured at one time, measurement indexes can be configured in a building block mode according to requirements, and chemical agents are not required. According to the device, the constructed digital optical fiber spectrometer is taken as a core, ultraviolet and visible absorption spectrum data of a water sample is processed in a mode of sequentially combining wavelet de-noising, principal component analysis and a support vector machine, and water quality indexes such as chemical oxygen demand and biochemical oxygen demand of water are acquired. Various physical and electrochemical sensors acquire water quality indexes such as ammonia nitrogen, dissolved oxygen and conductivity. All hardware and