Fecal E. coli comes from the intestines of human and other warm blooded animals and is excreted through feces. The survival time of fecal E. coli in natural environment was the closest to that of pathogenic bacteria, and the number of fecal E. coli in intestinal tract was the largest. Therefore, the content of fecal E. coli can better reflect the content of intestinal pathogenic bacteria in water, which meets the requirements of indicator bacteria for fecal pollution detection. Moreover, the survival time of fecal E. coli in water and its resistance to disinfectants and adverse factors in water are similar to those of pathogenic bacteria. In practical work, fecal E. coli is often used as an indicator to evaluate the sanitary quality of water. Fecal Escherichia coli on-line monitoring system is based on enzyme substrate microbial detection technology as the core, the development of water quality multi parameter microbial on-line automatic monitoring products. It is the first time that the laboratory enzyme substrate microbial detection technology is applied to the on-line automatic monitoring of water quality, which fills the gap at home and abroad. The product can detect the total number of colonies in surface water, groundwater, seawater and drinking water, total fecal E. coli, heat-resistant (fecal) fecal E. coli and E. coli, and can be combined at will. Break through the concept of single field water quality monitoring instrument, build a multi-purpose, arbitrary combination of field water quality automatic monitoring laboratory platform. Enzyme substrate microbial detection technology has the advantage of rapid online automatic detection, which can realize the online cultivation and detection of a variety of microorganisms within 6 ~ 18 hours. This product is suitable for: hospital sewage, drinking water source, surface water quality automatic monitoring station, sewage treatment plant outlet, etc.