In current practice, people determine whether or not pathogens exist in water by observing the color of the aquatic pathogen detection reagent through visual inspection; however, such a method is still unavailable for the quantification of pathogens. Moreover, a reagent reaction usually takes 24 to 48 hours to obtain a result. This technology, as proposed in this study, involves a portable multi-light aquatic pathogens detection device, which is designed and developed based on optical detection