Water quality monitoring system is a collection system which integrates data collection, storage, transmission and management. It is widely used in industrial and agricultural production, tourism, urban environmental monitoring and other fields. The water quality monitoring system is composed of six parts: water quality sensor, data acquisition instrument, communication system, power supply system, water collection system and water quality monitoring platform. It can simultaneously monitor water temperature, PH, dissolved oxygen, electrical conductivity, ammonia nitrogen, turbidity, COD, and many other water quality elements; Data acquisition instrument has data acquisition, real-time clock, data timing storage, parameter setting, friendly man-machine interface and standard communication functions.